anal tone
should exhibit good tone
what is haemolysis?
the rupture or destruction of red blood cells.
Do you think pericarditis can be treated? If so, how (remember the pericardium may contain many litres of pus)?
A rumenotomy to remove foreign bodyPericarditis - this has followed from penetration of a piece of wire from the reticulumDiagnosed on clinical examination and sometimes ultrasoundAntibiotic therapy will not resolve the pericardial infection although temporary reduction of oedema occurs after a single corticosteroid injection such as dexamethasone and antibiotic therapy.
ventricular tachycardia
A run of 3 or more VPCsRhythm usually regular during tachycardiaThe rate low but over intrinsic rate of the ventricles>40bpm in the dog>60bpm in the catMay be sustained or non-sustained
isovolumetric contractionsystole
All 4 valves shutVentricular pressures not exceeding the pulmonary artery and aortaventricular pressure exceeds atrial pressure causing the AV valves to snap shut.First heart sound S1From closure of the AV valvesVentricular pressure rises shown on graph
explain the difference between afferent neurons, interneurons and efferent neurons.
Afferent - towards the central nervous systemEfferent - away from the central nervous systemInterneurons - connect or associate one point in the CNS with another but never leave the CNS - used to transfer information between neurones
Bromide
Competes with Cl- in Cl channelVery old and long half life but takes a while to get to steady stateToxicity : gastric irritation, sedation, ataxia
diagnosis of canine lungworm
Complete blood countKnotts testThoracic radiographsElectrocardiogramArteriogramIndirect fluorescent antibodyELISATracheal washNot very specific as increased eosinophils can mean lots of things
Haematopoiesis
Continuous process of replenishmentFormation of blood cellular components Red blood cells = erythropoiesis White blood cells Plateletsprocess occurs in red bone marrow and spleen
how are dsDNA viruses produced
Double stranded DNATranscription of DNA viruses by cellular RNA polymerase, encode their own DNA polymerase so can control replication independent of cellular DNA replication.Assembly of virus buds from the nucleus.E.g. herpesviruses, adenoviruses
How can dysrhythmias be identified and treated?
Dysrhythmias are common in patients with heart disease. These will require characterisation with an ECG. Specific antidysrhythmic therapy may be required e.g. beta blocker, calcium channel blocker, digoxin- few areveterinary licensed.
myocardial hypertrophy
Eccentric hypertrophyOccurs with volume loadingEg valve incompetence/dilated CMOConcentric hypertrophyOccurs with pressure load - hypertension or narrowing of aortic or pulmonary valveIncrease in the thickness of heart wall
main innervation supply distal limb
Equine forelimb palmar aspect the median artery = main supply to distal forelimb which continues as medial palmar artery - no dorsal in horse forelimbEquine hindlimb plantar aspect the cranial tibial artery is the main supply to distal hindlimb continuing as dorsal metatarsal artery
venus return
Deoxygenated blood is returned to the heart. Diastolic cardiac volume is important to cardiac output. Important controlling factors: sympathetic nervous system, blood volume, muscle (respiratory) pump
identify the key factors in the epidemiology of Dictyocaulus viviparus (bovine lungworm) and Angiostrongylus vasorum (canine lungworm).
Dictyocaulus viviparus (bovine lungworm) Latter half of first grazing season Affects cattle on permanent pastures They have to malt twice to become infective from L1 TO L3 Causes parasitic pneumonia Alveoli damage
Why is nucleic acid synthesis a good target?
Differences in the organization and replication of bacterial DNA and RNA to eukaryotesQuinolonesNovobiocinAct on an enzyme which separates the two DNA strands - interfering with replication processRifampin - interferes with DNA-dependent RNA polymerase activity = prevents RNA synthesisbacteriostatic
indicator media
Different bacteria have different nutritional capabilities or enzymesThese differences can be used to make indicator media where once bacteria gives a colour reaction that others will notAllows differentiation of what is growing based on how they look on the media
pulse pressure
Different to blood pressureDifference in pressure that we see at the end of systole and at the diastoleInfluenced by arterial compliance (primarily in the aorta), stroke volume, ejection rate, consistent high pulse pressure will 'age' the heart quicker
gram stain
Differential stainStain one stain, de stains ground negative not ground positiveGram positive stay lighter pink colour
Describe the function of the distal limb skeleton
Distal limb consists of metacarpal or metatarsal bone and proximal middle and distal phalanges it is distal to carpus and tarsus
division of nasal cavity
Divided by scrolls of turbinate bone from nasal conchaeEvolved in mammals and birds as they developed endothermyThe hard palate evolved at the same time which allows sucklingIncreases surface areaBalance between airflow resistance, defence mechanisms, warming and moistening function and olfaction
dilator muscles comparison in species
DogCat - two more vertical bands of musclesHorse/ruminants - horizontal oval Extra structures - black masses suspended from pupil = corpora nigra and granula indica
eucoleus aerophiliusclinical signs and diagnosis
Dogs cats foxes hedgehogs etcInhabits trachea, bronchi and bronchiolesnormally asymptomatic but can have slight cough animal ingests an infective egg or earthworm (paratenic host) that contains an infective larva in its tissue then this goes to the lungs Diagnosis = faecal flotation of tracheal wash of eggs with characteristic bipolar plugs and a rough netted surface
the nasopharynx
Dorsal to soft palateSoft tissue continuous with palatine boneExtends from the choanae to the intrapharyngeal openingChoanae - opening of nasal cavity into nasopharynx
How does congestive heart failure develop?
Eventually the patient decompensates. Compensation and fluid retention results in congestive heart failure and disease progression.Clinical signs develop with time- months-yearsPatient compensates for disease initiallyGets progressively worseClinical signs vary
ectropion
Eversion or outward turning of the eyelidOpposite of entropionSaggy eyelidsOften doesn't need treatmentDiamond eye - mixture of both entropion and ectropion
what are neural tube defects?
Failure of neural tube closeAnencephaly = failure in cranial regionSpina bifida = failure anywhere else
Maternal antibody transfer test
Failure of passive transfer of maternal antibodies is the most common predisposing cause of neonatal infection. Foals which fail to obtain sufficient colostrum are susceptible to infection.Serum IgG levels of less than 400 mg/dl indicate significant failure of passive transfer of colostrum; ideally the serum IgG level should exceed 800 mg/dl.
Note the lack of blood supply on the dorsal aspect compared to the cow limb. What is the clinical significance of this structure in the cow?
In the cow, the axial palmer digital artery bleeds profusely when the digit is amputated so it must be ligated properly to avoid this.
alveolar duct
Has alveoli which open on all sidesHas no walls as suchCalibre of the alveolar duct is substantially greater than that of the respiratory bronchioleOpenings to the alveoli are guarded by rings of smooth muscle
Describe the positioning of dogs and cats for dorsoventral thoracic radiographs
Heart. Caudal edge of scapulae, caudal to back of ribcage. Keep back end square- twists the image of the thorax.Place in sternal recumbency.
Pulmonary Hypertension and D. immitis / narrowing of pulmonary artery
It is not caused by blockage but by hypertrophy of medial layer - thickening of wall of blood vessel Caused by disruption of intima leading to platelet influx and production of platelet derived growth factor PDGF Increases proliferation of medial smooth muscle cells and fibroblasts Thickening and hypertrophy of blood vessels
Identify potential problems of regional anaesthesia in the horse and ruminant
In the horse make sure we aspirate to make sure we are not in a blood vessel - pull the syringe back to ensure no blood comes outA ruminant has an additional blood supply along the dorsal aspect compared to a horse not - In the cow, the axial palmer digital artery bleeds profusely when the digit is amputated so it must be ligated properly to avoid this.In cows there is also a dorsal common digital artery in bovine forelimb and dorsal metatarsal arteries in hindlimb
increased vascularity
Increased vascularity: over-circulation results in lung fieldsmore radiopaque- left to rightshunts, fluid overload.
Ascaris suum in pigs
Ingest eggs containing secondary larvae stageWhich will hatch In small intestineBlood stream to liver and lungBreaks into alveoli-causing respiratory manifestationsCause irritation in lungsCoughed up larvaeSwallow larvae againLarvae become mature and live in the small intestine
Haemosiderin
It is intracellular complex of ferritin, denatured ferritin and other materialIron within deposits of hemosiderin is very poorly available to supply iron when neededLarge deposits may lead to organ damage
leucopenialowered levels of components
NeutropeniaLymphopeniaMonocytopeniaEosinopenia
leucocytosis increase in components
Neutrophilia - increase in neutrophilsLymphocytosis - increase total white blood cellsMonocytosisEosinophiliaBasophilia
Post-G SNSNerve fibreNeurotransmitterDesignationReceptor
Noradrenaline(Norepinephrine)Adrenergicα and/or β
function of retinal pigment epithelium
NutritionRecycling used photopigmentsForming part of blood-retinal barrierPhagocytic role in retinal inflammationStoring vitamin ARole in retinal inflammationMelanin pigment absorb stray light and scavenge free radicals
Iliopsoas - Iliacus
O: Cranioventral iliumI: Lesser trochanterA: Flex hipN: Femoral nerve and lumbar spinal nerves
Long digital extensor
O: Extensor fossa femurI: DP 2, 3, 4, 5A: Flex tarsus and extend digitsN: Fibular nerve
Cranial tibial
O: Extensor groove of tibia and cranial tibial borderI: Metatarsals 2 and 3A: Flex tarsocrural joint and rotate paw laterallyN: Fibular nerve
Pectineus
O: Iliopubic eminence and pubic tubercleI: Distal medial femurA: Adduct limbN: Obturator nerve
Middle gluteal
O: IliumI: Greater trochanterA: Extend and abduct hip. Rotate medially at hipN: Cranial gluteal nerve
Semitendinosus
O: Ischiatic tuberosityI: Distal tibia and tuber calcaneiA: Extend hip, flex stifle, extend hockN: Sciatic nerve
Biceps Femoris
O: Ischiatic tuberosityI: Proximal tibia and tuber calcaneiA: Extend hip, stifle and hock. Flex stifleN: Sciatic nerve
Fibularis longus
O: Lateral condyle tibia, proximal fibula, lateral epicondyle femurI: 4th tarsal bone and metatarsalsA: Flex tarsus and rotate paw mediallyN: Fibular nerve
Popliteus
O: Lateral epicondyle femurI: Proximal tibiaA: Rotate leg mediallyN: Tibial nerve
Gemelli
O: Lateral ischiumI: Trochanteric fossa of femurA: Rotate laterally at hipN: Sciatic nerve
Peroneus longus
O: Lateral tibia and fibulaI: Plantar aspect tarsusA: Flex hockN: Fibular nerve
Iliopsoas - Psoas major
O: Lumbar vertebraeI: Lesser trochanterA: Flex hipN: Femoral nerve and lumbar spinal nerves
Gracilis
O: Pelvic symphsisI: cranial tibia and tuber calcaneiA: Adduct limb, extend hip, flex stifle, extend hockN: Obturator nerve
Superficial gluteal
O: Sacrum and first caudal vertebra. Cranial dorsal iliac spineI: Third trochanterA: Extend hip and abduct limbN: Caudal gluteal nerve
Peroneus brevis
O: Tibia and fibulaI: 5th MT boneA: Flex hockN: Fibular nerve
Tensor fasciae latae
O: Tuber coxae and iliumI: Lateral femoral fasciaA: Tense lateral femoral fascia, flex hip, extend stifleN: Cranial gluteal nerve
External obturator
O: Ventral pubis and ischiumI: Trochanteric fossaA: Rotate medially at hipN: Obturator nerve
Identify the areas of the distal limb desensitised by common regional anaesthesia
Palmar region - the distal limb excluding the coronary band and the Abaxial region - does the whole digit including the band
ocular immune privilege
Protected from excess inflammation and the immune systemMechanisms for this: Limits access to the eye from blood ocular barriers Absence of lymphatics pathways : limiting access to lymphatic tissues Aqueous humour composition : ascorbic acid and other anti oxidants Immunomodulatory ligands on intraocular cells (esp. pigmented epithelial cells) Indigenous, tolerance-promoting antigen-presenting cellsCreate a stable environment
function of conjunctiva
Protects ocular surface allowing free movmenet of ocular structuresContributes to tear filmMost exposed mucous membrane in the bodyCALT is contained in everted lymph node - stroma = conjunctival - associated lymphoid tissueMany lymphocytes present which form active follicles when stimulated by antigens
heat-shock proteins
Proteins that help maintain integrity of other proteins that would normally be denatured in extreme heat.Form hormone - receptor complex which causes conformational changeCrosses through nuclear membrane releasing receptorHormone eg testosterone acts at nucleus causes transcription making more hormone
functions of ciliary body
Provides accommodation - allows us to focus on close up and far away thingsDistance - ciliary body relaxed contracts lens
Identify other professionals supporting musculoskeletal care of birds
RSPB AND RSPCA, local councils
Purkinje fibres
Rapid conduction tissue Ensures simultaneous contraction of ventricles From apex to base is how depolarisation spread Electrically excitable cellsSimilar to cardiac myocyte action potentialRetains spontaneous activity as a result of sodium leakage
tapetal hyper reflectivity
More reflection and abnormal reflectionDilated pupilsNo signal going up optic nerve
myotatic reflexes biceps
Reflex contraction of the biceps musclesCauses reflex flexion of elbow, increased tension in tendon of insertion, movement of skin over muscle belly
cardiac valves
Right AV = often called tricuspid Three cusps but most species only have two cuspsLeft AV - often called mitral 2 cuspsAttached by chordae tendinea - papillary muscles
Explain the concepts of organisation of the spinal cord pathways in tracts
Similar fibres and axons are arranged in tractsTract is just a bundles of nerves that are organised together in functional bundle / tractsWe can map out a no of different tracts that relay the same informationBe aware of organisationsomatotopic organization?organisation within the tracts
diagnostic tests (logical process)
Start pointClinical signsVisual/imagingEndoscopyRadiographyUltrasonographySamplingHaematologyBronchoalveolar lavageTracheal aspirationSwabMicrobiology on samplesCytology - demonstration of immune cellsCulture or visual - bacteria/fungiDemonstration of viral antigens
what are the vagosympathetic trunk components?
Sympathetic fibres running cranially to head/neckParasympathetic fibres running cranially from receptors and viscera to headParasympathetic fibres running caudally to heart and visceraFibres from CN XI that will form the recurrent laryngeal nerve to laryngeal muscles - hitchhiking form recurrent laryngeal nerve
what happens during ventricular systole
The ventricles contract, pushing blood through the semi-lunar valves into the pulmonary artery or aorta
What happens during ventricular diastole?
The ventricles relax, allowing them to fill with blood at the same time as the atria contracting
Describe the components (epidermal-dermal and endochondral) of the chelonian shell and its relationship to the axial skeleton
The vertebral column forms the under the surface of the carapace it is made up of dermal and endochondral bone - metabolically active with blood and nerve supply, turtle shell attached to axial skeleton it is formed of scutes which are the epidermis
function of the thymus
Thymic education and central tolerance of T-cellsT cells must be prevented from reacting to 'self' antigen - would lead to immune system overreacting
dorsal supply of distal hindlimb
Two nerves supply - so you have to block dorsal aspect as wellNerve supply to dorsal aspect of hindlimb different to the forelimb as in the forelimb the radial nerve terminates at carpus and dorsal supply comes from medial and ulnar nerves - can be blocked on palmar aspectIn hindlimb the fibular nerve supplies dorsal aspect and must be blocked on here
reciprocal apparatus
Two tendinous cords cause united movement of the stifle and hockThe tendons arePeroneus tertius (front)Superficial digital flexor (back)Anytime we're going to extend the stifle pully structure acts on tarsus
what do we need to know from the life cycle?
Type of life cycle (direct or indirect)Definitive hostIntermediate host (if any)Infective stageRoute of infectionUnique morphological featuresUnique epidemiological featuresClinical signs, pathogenesis, control!!!!!
what are viruses composed of ?
They are composed of nucleic acid surrounded by a protein coat
mycoplasmas analysis with gram positive bacteria?
They lack a cell wall so they do not stain as gram positiveThey have reduced genomes and have got rid of a lot of their genes except for a limited number of essential components and pinch other metabolites from host environment
anatomy of choroid
Thin and vascularThree vessel layersFunction of choroidSupplies blood to the retinaPart of blood-ocular barrierIncludes the tapetum : reflecting light back to retina to improve vision in dim light
what is the outflow from the CNS does the sympathetic ns have?
Thoracolumbar outflow The neurons begin at the thoracic and lumbar portions of the spinal cord
Central Vestibular Lesion
Same as peripheral vestibular dysfunction but also cerebellar dysfunction (e.g., intention tremor), proprioceptive deficits, mentation changes, vertical nystagmus, and cranial nerve deficits other than VII, VIII and Horner's syndromeNystagmus tends to be positional with central lesions as well. However, positional nystagmus also occurs with chronic peripheral vestibular disorders.
Give the two names of neuroglia in the peripheral nervous system and explain their function
Schwann cells - provide myelination to peripheral neuronsSatellite cells - are for repair (Adult stem cells)
Sympathetic Mechanism on the Heart- to increase the heart rate
Second messenger - cAMPB1 receptorCalcium channels open more and for longer and therefore more Ca2+Increased contraction forceCalcium channels open earlier so reach threshold potential and reset quickerMore likely to produce a beat and heart rate increases
Identify the four features of Tetralogy of Fallot
Ventricular septal defect (VSD)Pulmonary valve stenosisA misplaced aortaA thickened right ventricular hypertrophy
Pneumothorax definition
accumulation of air in the pleural space
what can heart disease be?
acquired or congenital acquired occurs later in life and is more common
where are lymph nodes located
at various points along lymph vessels, act as elaborate filtersCattle and dogs have fewer, larger nodes whilst pigs and horses have lots of smaller nodes
amygdala
almond shaped groups of neurones located deep within the medial temporal lobes within the brainPart of limbic systemDamaged amygdala can cause people not to show anxietynuclei of amygdala
Characteristics that confirm S. pneumonia
alpha haemolysisnon-motilecocci that form chainsfacultative aerobegram positive
ischaemia
an inadequate blood supply to an organ/part of body
Ethrocyte Sedimentation Rate (ESR)
an increase in ESR is a non specific change in many diseases that is probably due to changes in the plasma that encourage agglutination - the larger aggregates that sediment more rapidly
what increases afterload
an increase in stroke volumeit is influenced by pressure of blood in circulation and is affected by vasomotor tone and primairily arteriolar tonelow afterloadmay occur after loss of bloodMeans we can increase the stroke volumeDue to less resistanceincreased afterloaddue to increased resistance within vascular systemStroke volume compromised and reduced
what is an inflammatory response
an innate immune reaction that ensures immune cells and other substances are brought to the infected areaWhat does the inflammatory response do?destroys foreign organismsremoves injured tissue or cell remnantsprovides favourable conditions for healing
Poikilotherm
an organism that cannot regulate its body temperature except by behavioural means such as basking or burrowing
Homeotherm
an organism that maintains its body temperature at a constant level, usually above that of the environment, by its metabolic activity
signs of vestibular disturbance
animal not walking in straight linecircles to certain sidehead tilt
what do paraventricular and supraoptical nuceli both synthesize?
antidiuretic hormone (ADH)/vasopressin and oxytocine
what happens to haemoglobin in higher concentrations of oxygen
colour brighter and redder
variable in CSF = colour normal finding change due to bacterial infection?
colourlessWill change to cloudy if there is a elevated cell countPink or red discolouration is commonly due to iatrogenic blood contamination
what are the hemispheres of the telencephalon connected by?
commissurescorpus callosum is the biggest connection between two hempishpheres
mucous membrane colour
estimation of oxygen content from mucous membranes colourCyanosis - blue/cyan colour = serious problemIndicated deoxygenated haemoglobinMeasuring oxygen content - pH, HCO3, PaCO2, PaO2
urachus fetal role and remanant
fibrous remnant of the allantois, a canal that drains the urinary bladder of the fetus that joins and runs within the umbilical cord
what are the journeys for general and special sensory information
general and special sensory information = relays through appropriate groups of thalamic nucleigeneral = through ventral groupspecial = geniculate nucleiimpulses then pass via the internal capsules and visual and auditory radiations to reach appropriate cortical sensory areas
define what the term osteochondrosis means and recognise that it is a developmental disease
group of developmental skeletal disorder of unknown origin that primarily occurs in horse dog and pigfocal failures of endochondral ossification that occur in well defined predilection sites in young animalsdevelopmental disease means only occurs in developmental period
what does endoderm form?
gut, liver, lungs
what does surface ECG record and how ?
recorded with one pair of electrodes either self adhesive pads or crocodile clips Bipolar leadsPositive and negative electrodesThey are called limb leadsOne - RF and LF - positiveTwo - RF and LH - positiveThree - LF and LH - positive Earth lead on hindlimb
location and function of DDFT?
runs deep to SDFTpasses through manica flexoria inserts on flexor tuberosity of distal phalanx of each functional digitflexes distal digit
latent infection
infectious agent disappears and lays dormant but can be reactivated
parasympathetic action on atrioventricular node
lengthens AV delay decreasing AV conduction and lengthens AV node refractory period = not depolarised as quickly and can make refractory periods increase
topography of hypothalamus and function
lies below the thalamusforms ventral part of diencephalonexposed on ventral or basal surface of braininvolved in appetite, eating and metabolismhypothalamusmaintaining homeostasis
what are the organs involved in regulation of external acid-base balance?
lungs and the kidneys
location and function of long digital extensor - hindlimb?
main digital extensor for hindsplits into branches for each functional digitinserts on extensor process of distal phalanx
ossicles of middle ear
malleus, incus, stapesthey act as levers to transmit the sound wave vibration
left semilunar in aorta
often called aortic valve
right semilunar in pulmonary artery
often called pulmonic valve
commensalism
only one organism benefits from this association without causing any harm to the second organism eg fish which live within the tentacles of sea anemone
anastomosis
organs rely on blood flow if the flow stops the organ becomes necrotic to avoid this organs can receive a collateral supply of blood : anastomosis
Neocortex
outermost layer of cortexDominant part of cerebral cortex in mammalsPlanning of movement, perception, learning and memory
where can you take swabs in dogs and cats?
nasal swab, oropharyngeal swab, tonsillar swabCan be used when investigating a chronic tonsillitis, chronic nasal discharge or other suspected infectious agentIn cats and some dogs it is hard to obtain tonsillar swab from conscious animal
metabolic alkalosis
pH has increased and increase in bicarb (Increase in HCO3-)Some types /causes of vomiting due to loss of acid as HClCan occur due to diuretics : H+ ions loss from the kidney
neocerebellum - 3
part of hemisphereinput coming via pons
what is the lymphatic system?
part of the circulatory systemnetwork of capillaries, vessels,Mechanism for removing excess interstitial (tissue) fluidTransportation of fatsImmune defence
what is simple pseudostratified epithelium?
secretion and movement of particles along tubular organs found in trachea, bronchi, epididymis
nuclear sclerosis vs cataract
nuclear sclerosis Nucleus becomes denser and harder (sclerotic) with age d/t continual production of new lens fibresGreyish blue hazeNo classification systemMinimum effects on vision - reduced accommodation (presbyopia)No effects on ocular healthSurgery not requiredcataractAny opacity of lens or its capsule - variable pathogenesisVery variable appearanceComplicated classification- age of onset, aetiology, extent, positionVariable effects on visionMay cause lens-induced uveitisMay need surgical removal
stroke
occurring when blood flow to an area of the brain is cut off.
three categories of anticholinesterases?
short actingmedium durationirreversible
sympathetic action on atrioventricular node
shortens AV delay which increases AV conduction and shortens AV node refractory period = more rapid depolarisation
tail function
should be good tail tone and function with no reduction in tail carriage
complement protein
substance that is produced by a predecessor protein or in response to the presence of foreign material in the body and that triggers or participates in a complement reaction
reservoir host
temporary hosts used in the absence of natural host eg human trypanosomes reservoir in cattle and antelope
Expiratory reserve volume (ERT)
the additional volume of air that can still be exhaled after a normal exhalation, for instead in a forced breath out.
Inspiratory reserve volume (IRT)
the additional volume of air that can still be inhaled after a normal inhalation.
what is PCR used for?
to amplify DNADNA is heated with primers to denature the DNA strands. On cooling, they anneal and the primer sticks to the template if the gene is present. DNA polymerase fills the gap, adding nucleotides to the 3' end and extending the primers.
ventilation
total ventilation is the tidal volume x respiratory frequency
exogenous pathogens
transferred from other sources
Total lung capacity (TLC)
the maximum volume of air that the lungs can hold accommodate after maximum inspiration, so it is the total of the vital capacity and the residual volume.
what will the neural plate form?
the neural tube - neurulation (edges fold around and meet in the middle)
how do most DNA viruses replicate in?
the nucleus
palpebral fissure
the opening between the eyelids
what two pathways exist for a compound to transverse the epithelial sheet from the intestine?
the paracellular pathway = between the cellsthe transcellular pathway = straight through the cell
deadspace ventilation
the portion of VE that is not available for gas exchangeDEAD SPACE VOLUME X FREQUENCY OF BREATHING
spiral septum
septum between aorta and pulmonary artery grows on downwards clockwise spiral then vessels enlarge truncus expands and two channels are separate - pulmonary trunk and aorta
eosinophil
circulates in bloodprotective role against parasites
corpus callosum function
corpus callosum is the biggest is major connection between the two hemispheres it is a large C-shaped nerve fibre bundle found under the cerebral cortex
what does histamine do?
dilates blood vessels and permability of vessels and activates endothelium leading to warmth redness, local oedema (swelling) and attraction of other inflammatory cells to site of releaseclinical signs of histamine release?irritation of nerve endings leading to itching or pain
what is rate of diffusion inversely proportional to
distance over which diffusion occursand thickness of membrane
what is the role of the lacrimal puncta
drains tears
Why does plasma lactate levels increase in septic shock
due to decreased perfusion of tissues and a shift towards anaerobic metabolism.
S wave in ECG
end of ventricular depolarisation happens endocardium to epicardium gives S wave from small part
Osteochondrosis :
failure of endochondral ossification
list disease conditions which affect ovine foot
foot rot and scald
properties of specific nuclei
have well defined sensory and motor functionshave highly organised point to point connection with sensory and motor regions of cerebral cortex
competitive ELISA
if antigen is small and has only one epitope (binding site for antibody). The sample antigen competes with labelled antigen for antibody binding site, ie cortisol
what leads to pressure or even oedema in either pulmonary or peripheral
if more blood enters the left or right ventricle as they are matchednormally cardiac output is related to the left ventircle
respiratory effect in anxiety
important functionDeep accelerated breathing helps prepare for flight or fight as tissues of human body need more oxygenAvailability of glucose is increasedIncrease in sweating
where do most RNA viruses replicate?
in cytoplasm
difference in species in distal limbs
in horse interosseous is entirely tendinous but in dog and cat it is musculardifferent ray patterns as abaxial digits lose contact with the ground in faster animals that are adapted for speed reducing muscle massdifferent numbers of metacarpal bonesinterossei III and IV fused in cow - separate and insert on corresponding digitsin cows there is also a dorsal common digital artery in forelimb and dorsal metatarsal arteries in hindlimbstump of axial palmar artery bleeds profusely and must be ligated
what allows the development of immunoassays?
specific antibody in infected animal- anti-virus antibody in blood samples from infected animal - virus in the assaydetection of pathogen with a specific antibody - virus in biological sample from infected animal - anti-virus antibody in the assay
non invasive measurement of measuring the arterial blood pressure
sphygomomanometry- inflation of a cuffoscillometric-at is restrained and has a blood pressure cuff around its leg, the width of the cuff is actually quite important it should be about 50% of the circumference of the leg that is being measured. Calculates systolic and diastolic pressure and heart ratedoppler- probe that is placed on clipped area of where we can feel pulse (paw/tail) we get a whooshing sound out of microphone
exercise physiology of sprint, standard and long distance
sprint relies totally of anaerobic process in muscles breaking down ADPstandard switches to anaerobic glycolysis for 15-30 seconds after dominant aerobic processes for first 30 seconds of racecauses acidosisaerobic after 30 second anaerobic interval againfading at the end caused by metabolic acidosis
where are TLRs embedded
in lipid bilayers :- outer cell mebrane - vesicle membrane
perineal reflex
stimulation of perineal region should elicit winking/constriction of anal sphincter
what happens in the lung when altitude increased
increased pressure pushes fluid from vessels into alveoli- we get fluid flooding the alveoli impacting on the ability of oxygen to reach alveoli so impacts gas exchange bacterial growth risk for animals with fluid being pushed outincreased
eucoleus (capillaria) boehmi
infects mucosa of nasal cavity/passages and the fronal and paranasal sinuses dogs and foxes
what is uveitis
inflammation of the uvea
what are all effect fibres from the cerebellar cortex (Purkinje cells)
inhibitory
four types of stratified epithelium?
stratified squamous, stratified cuboidal, stratified columnar, transitional epithelium
where is it found and what are the properties of fibrocartilage
intervertebral disks and certain ligaments and tendinous attachments to boneNo true perichondrium , alternative layers of fibrous and cartilaginous tissue
baroreceptors
involved in regulation of homeostasis they are located in the internal carotid arteries and in the wall of the aortic arch
exophthalmos definition - Globe size (normal/enlarged/reduced)Globe position (normal/protruding/sunken)Appearance of eye itself (normal/abnormal)
is a bulging of the eye anteriorly out of the orbitNormalProtusionNormal
hydrophthalmos definition - Globe size (normal/enlarged/reduced)Globe position (normal/protruding/sunken)Appearance of eye itself (normal/abnormal)
is primary congenital glaucomaThis form of congenital glaucoma is usually bilateralNormalNormalabnormal
fixed acids
An acid which cannot leave solution and must be eliminated via the kidney, e.g. phosphoric acid.
List different considerations when selecting, prescribing and dispensing different drugs
Correct indication (correct problem) with no contra-indications - safe and effectiveEfficacyRoute of administrationLegalisationStatus of animal - young old pregnantShort or long term therapyCostOwner educationFarm animal
Full Agonist vs Partial Agonist drug concentration
Full agonist increase responses as we increase concentrationPartial agonists same shape but less effect
draining lymph nodes of head and respiratory tract
Head:ParotidMandibularRetropharyngealThorax:Tracheobronchialdeep in chestview radiographicallymeat hygiene inspection
Describe how to safely and effectively apply an equine foot bandage
Heal to toe direction and around the circumference for full coverage of foot followed by a cohesive layerEnsure no elasticated bandage contacts skinMake duct tape square and apply to foot
corium/dermis
Highly vascular dense connective tissuePapillae produce hollow horn tubulesGrows like normal dermis/epidermisStart of lamellae next to the papillae
histograms
Interpretating histogram - unimodal data with obvious median, mean and mode value of sixMulti modal data on the right
Semimembranosus
O: Ischiatic tuberosityI: Distal, caudal, medial femur and proximal, medial tibiaA: Extend hip and flex or extend stifleN: Sciatic nerve
oxidase test
Oxidase test identifies bacteria that produce cytochrome oxidate An enzyme of the bacterial electron transport chain used by bacteria growing aerobically Colour comes from reduction of test compound
myotatic reflexes patellar
Percuss the straight patellar tendonReflex extension of the stifle
what are the functions of the cerebral spinal fluid?
Protection - of the brain as there is a selective barrier between the blood and the CSFSupport - gives buoyancy to brain for mechanical damageNutrition - CSF goes into tissues of the brain and takes in nutrition
Identify the main features of the bones and joints of the distal limb
StrongSynovial jointsCollateral ligaments presentAngled to groundShould be parallel
What occurs to the valves at the end of ventricular systole?
all valves close again
what is virus isolation in cultured cells testing for?
detection and measure of infection virus
Define the main divisions of the enteric nervous system?
enteric controlGIT
myelencephalon
hind brainmedulla oblongata
three variables that define anaemia?
total haemoglobin, PCV or haematocrit and RBC count
indirect ELISA
used to detect a specific antibody in sample
labatory diagnosis of viral infections
isolation of the live virus and replicate it nucleic acid detection using molecular techniqueselectron microscopy immunological techniqueshaemagglutination diagnostic serology
what is iron assembly and release - viral budding?
- envelope of many enveloped viruses originate from host membranes acquired during virion assembly and egress (leave)
paleocerebellum -2
limb movement and coordination
endo-parasite
lives internally inside the host eg worms, protozoa
recurrent laryngeal nerve (RLN)
CN XI branch (the hitchhikers)- leaves at vagal trunk of thoraxRight RLN hooks around right subclavian arteryLeft RLN hooks around aortic arch
heart muscle disease
CardiomyopathyDevelops later in lifeUnknown causeUsually develop heart failure
coronary sinus
Empty into the right atriumDeoxygenated blood back from heart itself
gram negative
Has a membrane, cell wall, another membrane This membrane has lipid polysaccharides on the outside That bacteria is unique for this component
How is excess interstitial fluid removed
In capillary beds fluid and dissolved gasses are passing out of circulatory capillaries into the tissues
How is speed optimised?
Increase stride length and increase stride rate
Cranial nerve X - Vagus
Less important doesn't factor in exam
M-mode left ventricle
Looked at how these structures move over time through each cardiac cycle
what do you need?
Low frequency (Depth) ultrasound probe 2.5MHz Concurrent ECG attached to the skinPhased array (sector)Dedicated machine Capable of imaging to 30 cm at leastPatienceStocks
dirofilaria immitis life cyclecanine heartworm
Mature parasite sexually reproduces in heart and vertebraeOffspring they produce is microfilariae
Bundle of His
Penetrates annulus fibrosisHas two branchesOnly electrical pathway between atria and ventricles
carbon dioxide transport
Physically dissolved in blood - 10%Carboxyhaemoglobin on proteinsBicarbonate ions in plasma
bacteria / septicemia
Presence of viable bacteria in blood stream
angiography - selectiveRV
RV insert catheter into jugular vein
malt and galt
Secondary lymphoid tissuesPeyer's patches - lymphoid tissue specifically located in the wall of the intestine
Cranial nerve VII - facial nerve
Some degree of facial paralysis - largely motor fibres
Cranial nerve I - olfactory nerve test
ability to scentowner observation normally
endogenous pathogens
already on the animal
define sign stimulus
the description of simple key features of an organism that bring about a particular response
white line
the junction of the "sole" and the "wall" and an inherent area of weakness
closing capacity
the minimum volume of air needed to keep the alveoli open
tracheal wash why do we do it
with the cat under GA, a sterile ET tube is placed and then washed with 2-3 ml aliquots of sterile saline. Any secretions are collected and submitted for C+S and cytological examination.Possible findings as for BAL.
RBC morphologyhaemoglobin contentHIGH MCHCNORMALLOW MCHC
hyper chromicnormochromichypochromic
permissive host
not usually used by parasite but still favours life cycle completion eg liver fluke
inflammation in the CNS
'-itis'Infectious vs non-infectiousNot every inflamed brain is due to an incoming infectious agent attacking the brainIncreasing no. of autoimmune diseasesBacteria, viruses, fungi, protozoa, parasites, prions, auto immune (NME, GME, NLE, SRMA)
how is the interferon response activate in innate immunity?
(type I interferons are cytokines that play a crucial role in host defence against viral infection)- induction involves activation of PRRs (pattern recognition receptors)- binding of PAMPs leads to activation of interferons
how do viruses hijack host cell machinery to suppress host gene expression?
- to enhance replication, translation and produce progeny virus particles- viral polymerase RNA virus captures host RNA polymerase II to initiate transcription- expresses end-ribonuclease PA-X that takes over RNA splicing to selectively target host RNA for destruction
variable in CSF = RBC countnormal finding change due to bacterial infection?
0sign of bleeding - may also due to spinal tap needle hitting a blood vessel
two parts of vascular tree
1- The systemic circulation2- the pulmonary circulation
SIRs, sepsis and infection
1. A localised infection turns systemic i.e mastitis 1 in 100 cases sepsis occurs as consequence of mastitis in dairy cattle2. Mucosal barrier breakdownSepsis as complication due to commensal bacteria after breakdown of barrier ie ischemic intestineCan happen due to:NeonatesSome colic cases in horses (twisted gut)Long surgery (human)
anatomy of retina
10 layersretinal pigment epithelium (RPE)outer most layer which lies in front of tapetum and neurosensory layers comprises the 9 other layers
monocytes histology
15-20 micrometresIrregular shaped nucleusLacy reticulated chromatinBlue - grey cytoplasm
Questions to ask at arrival for neuro exam
Acute or chronic - has it started recentlyTraumaAny animals in the flock with similar problemsOften worth looking at the field/feed/flock - inspect environment
selective indicator medium
A combination of selective and indicator media
radiograph of dog with A.vasorumhow should it be treated
fenbadazole, moxidectin, milbemycin
transport medium
A medium designed to protect the organisms in you sample on the way to the lab.
Heart diseasewhere is it common?what does it involve?
A syndrome in which the heart fails to deliver blood effectively to meet the requirements of metabolising tissuesIs common in small animal and equine practiceIt normally involves valve degeneration and the valve becoming incompetent or diseases of the heart muscle, resulting the heart not contracting well or not filling wellDoes not always result in heart failure
neuropharmacology
About drug-induced changes in the functioning of cells in nervous system
Post-G PSNSNerve fibreNeurotransmitterDesignationReceptor
AcetylcholineCholinergicMuscarinic Ach R
Pre-G PSNSNerve fibreNeurotransmitterDesignationReceptor
AcetylcholineCholinergicNicotinic Ach R
Pre-G SNSNerve fibreNeurotransmitterDesignationReceptor
AcetylcholineCholinergicNicotinic Ach R
Describe a test used to assess haemostasis
Activated coagulation time- 2ml blood in ACT tube containing contact activator, warm (37°C). Check for clot formation every 5-10 seconds. Record time that clot forms. Check reference range for the tube type. Simple in-practice test, less sensitive than aPTT.
parasympathetic Mechanism on the Heart- to decrease the contraction
Actively opposes Beta1 receptors - reduce cAMPThis slows the heart Reduce automaticity which slow conduction at AV node Decreased contraction Over riding vagal tone - over stimulated parasympathetic system causing heart rate to be too low
What are the two types of heart failure and what is the pathophysiology?
Acute- rare- vascular disease and acute myocardium more common in humans.Chronic- most common- usually degenerative conditions.Whatever the cause is, cardiac output falls and is detected as a fall in blood pressure.Degenerative valve disease- regurgitation means less forward flow into aorta.Dilated cardiomyopathy- forward flow falls due to poor contractility.Restrictive/hypertrophic cardiomyopathy- forward flow falls because heart cannot fill.
List the 4 steps involved in bacteria infection and disease
AdhesionInvasion - intra/extracellular survivalSubversion of host defenceReplication - either leading to long term survival in the host or spreading to further hosts
Mucosal associated lymphoid tissues (MALT)
Aggregation of lymphocytes under ciliated epithelium
Bronchus associated lymphoid tissues (BALT)
Aggregations of lymphocytes beneath non-ciliated epitheliumStrategically located at bifurcations of bronchi (turbulence and deposition of particles) to sample deposits
importance of C3
All three pathways converge on C3Made by macrophages in the liverHighest concentration of serum complement proteinsC3 breaks down into C3a and C3b C3b Can bind microbe surfaces via carbs Can bind factor H on host cells taking C3b out of circulation C3a Acts as an anaphylatoxin or a chemoattractant - attracts leukocytes to area of infection
What occurs to the valves at the end of ventricular diastole?
All valves are closed until pressure in the ventricles exceeds pressure in the aorta/pulmonary artery.
Isovolumetric Relaxationdiastole
All valves closedSecond heart sound - S2Ventricles empty so pressure fallsDrops below pulmonary artery and aortaPulmonic valve and aortic valve shut Causing second heart sound
In a sandwich ELSIA, what would happen if the blocking step was omitted?
All wells, including the negative control wells, would show uniform overdevelopment
hypoventilation
Alveolar oxygen pressure (PaO2) decreases while PaCO2 risesThe patient breathes less so carbon dioxide is blown less and it starts to accumulate leading to hypercapniaIncrease in the carbon dioxide (hypercapnia) leaves less space for oxygen in the alveoli so the hypoxia increasesHyperventilation means we get rid of our carbon dioxide very quickly and we can end up hypercapnic
alveolar dead space
Alveoli incapable of gas exchange (in a healthy animal that is quite negligible)
Define cardiac output. What two major factors determine the magnitude of cardiac output?
Amount of blood pumped in 1 minute measure in ml/minAffected by heart rate and stroke volume
volatile acid
An acid which can leave solution and enter the atmosphere, e.g. carbonic acid - in the lung, broken down into CO2 and H2O.
blood agar
An enriched media it has to be cooled prior to adding sterile blood so it does not lyseWhen grown on blood agar some lyse (brake open) or damage blood cells to access iron
State the indications and contra-indications of performing nerve blocks in the horse
Analgesia of these nerves can selectively eliminate or "block" portions of the limb from sending sensations of pain to the brain. A horse with a lameness is considered to have "blocked sound" when the lameness that was seen originally is eliminated by local anesthesia. Using this principle, veterinarians are able to identify the specific location on the limb responsible for the horse's pain and subsequent lameness. Therapies can be directed to exact locations and lamenesses can be resolved.
short axis view of the left atrium
Angle up more dorsallyMercedes sign3 cusps of aortic valve
what happens in the response to haemorrhage what are the indirect endocrine effects
Anti-diuretic hormone - ADH released from the pituitary in response to reduced blood volume Causing vasoconstriction and retention of circulating volume through the kidneysAngiotensin II Increases blood vessel toneErythropoietin (EPO) Stimulates erythropoiesisAtrial natriuretic peptide (ANP) Released from cardiac myocytes in response to diastolic stretch Increases water excretion Blocks aldosterone, ADH and adrenaline release
immunological techniques
AntibodiesSerotyping - Salmonella E.coli LPS FlagellumStaining with specific fluorescent antibody
Reduced Ejectionsystole
Aortic and pulmonary valves open - AV valve remains closedDecline in ventricular ejection
Define arrhythmia and dysrhythmia
Arrhythmia- a condition in which the heart beats with an irregular or abnormal rhythm.Dysrhythmia- an abnormal rhythm.
Sympathetic innervation directly to the heartRelease of NA
Arterial blood pressure at the top has increasedThis is due to increased cardiac outputHeart rate increasedHaven't affected the cardiovascular system
bronchiole to bronchus
As for the bronchus, consider it's histological structure in relationship to it's function. Bronchi diminish in diameter the structure progressively changes to resemble more closely that of large bronchioles Bronchi needs to remain open all the time and be strong in order to make sure the animal is able to respire This is achieved by the cartilage surrounding the bronchusHow does it differ from a bronchus? Bronchiole is an airway of less than 1 mm diameter which has neither cartilage of submucosal glands in its walls Epithelium is composed of ciliated columnar cells and few goblet cells Bronchioles lack cartilage and glands Bronchioles are thin walled airwaysWhat are the similarities? Both have smooth muscle
fran starling mechanism
As we increase preload we will increase stroke volumeBecause ventricular muscle stretching leads to a stronger contractile force : Frank-Starling Mechanism
long axis view of the left ventricular outflow tract
As we move cranially we lose out right atrium and we see the aortaCalled aortic view
what is the role of the autonomic nervous system
Automatic processes but modifies eg heart rate and blood glucosePart of the PNS supplying efferent (motor) fibres to 'visceral structures' ie GVE fibresParasympathetic Local control of action eg urination, salivary glands, GIT and heart rateSympathetic General increase in alert state - fear, flee, fright, fun and frolic Widespread effects
Activation of cardiovascular system during anxiety
Autonomic nervous systemincrease in heart rate and strength of the heart beat Crucial in preparation for fight and flight as it pumps blood more rapidly to the needed areas of the body
Outline the course of vascular supply on the distal limb
Axially artery - brachial artery - medial artery - medial palmar - medial and lateral palmar digital
Ganglion cells
Axons make up the optic nerveCover whole area of retina but miss out fovea forming around it to allow highest visual acquityLight hits the first in the retina
B - mode ultrasound
B - Mode UltrasoundReal time slice through tissuesQualitative assessment for functionMeasurement of chamber dimensions (LA)
ocular ultrasound indications
B- mode USCommon indications Very useful to image the inside the globe when you cannot see into the eye eg cloudy cornea, cataract Measure globe size Assess orbital disease eg retrobulbar abscess, FB
What types of heart failure are there and which are most common?
Backward failure (congestion)- more common and chronic vs forward failure (poor perfusion)- rarely- acute.Left heart failure- congestion of the pulmonary venous circulation- drain the lungs- pulmonary interstitial of lungs and into alveoli.Right heart failure- congestion of the systemic venous circulation- drain the body. Fluid leaks into body cavities.Left more common- diseases affect L more than R and is moresignificant. L is high pressure- effect more obvious. Fluid in lungs is life-threatening.
prokaryotic
BacteriaGram negative (Gram -Ve)Gram positive (Gram +Ve)Acid fast (Mycobacteria these group with Gram +ve)Mycoplasma (No cell wall)
why do commensals cause disease?
Bacteria are able to alter their gene expression Switching genes on and off so they can have different properties = Phase variation Often triggered by some form of stress on the bacteria = Eg turning on adhesion factor increasing colonisation of lungHost controls impaired Changes in host, pregnancy, stress, injury Environment related Co-infection with other pathogen - incurrent disease =All allow opportunity for infection through reduced immunity =Eg dehydration to increase mucus viscosity which slows escalator and reduce function in clearing commensalsWhy does disease manifest its self?Multiplication of an organism exceeds the threshold for removalWhen an organism is 'pathogenic' they can actively invade or damage tissue
what happens at altitude?
Barometric pressure and alveolar oxygen tension falls as altitude increases
Understand the preparation and environment required to obtain good ultrasound images
Be able to trim the foot and when placing ultrasound gel use a lot and make sure it has time to settle in to the skin
Produce a basic flock health plan
Be careful with which sheep are introduced to the farm as this will spread bacteriaAntibiotic injections and constant check of any mechanical damage to sheep feetWhen introducing new sheep quarantine for 14 days
Muscarinic agonists
BethanecholPilocarpineacetylcholinethey are slowing the heart rate, causing contraction of smooth muscle - increasing peristaltic activity in GI. Sweating, lacrimation, salivation and bronchial secretion clinical use - glaucoma
what are short vertebral ligaments
Between the spinous processes = interspinousBetween transverse processes = intertransverseBetween vertebral arches = interarcuate/flavum
four types of pattern seen on radiographs
Bronchial patternAlveolar patternVascular patternInterstitial patterns- diffuse (unstructured/fine structured), nodular
Benzodiazepines
Bind to GABA a receptors facilitating endogenous GABA effectsToxicity : sedation, CV and respiratory depressionThey are developing tolerance makes them unusable for epilepsy but used for status
Barbiturates
Bind to GABA receptor-Cl channel complex increasing power (potentiating) of GABACan be toxic: sedation, nystagmus, ataxia but normally go away after few weeks
neurosensory layers bipolar cellshorizontal and amacrine cells muller cells
Bipolayer cells : relay visual signal, first neurone in visual pathway pass signal to ganglion cells which axons go on to form optical nerveHorizontal and amacrine cells : modulate neuronal activityMuller. Cells extend across whole retina
lymphoid organs in birds
Birds have fewer lymph nodes and many species of bird have noneLymphatic vessels are also less numerousBursa of fabriciusSac like structure on dorsal surface of cloacaPrimary lymphoid organ similarly to thymus it regresses with age
blood ocular barrier
Blood aqueous barrier and blood retinal barrierthe purpose is to provide a good blood supply to the eye but limiting the cells and proteins that can enter the eye
In what direction will blood flow across the following structures in an adult? Ventricular septal defect
Blood passes from the left ventricle to the right side of the heart
Clinical signs due to failing right ventricle
Blood starts to 'back-up' in system and this increases pressure in peripheral veins Jugular distension Peripheral oedema - in cattle usually around the brisket Pleural effusion - which worsens hypoxaemia even further
information projecting to the cerebellumand damage to cerebellum
Bottom of cerebellum we have the flocculonodular lobe which has some vestibular nucleiDamage to cerebellum can cause problems = paradoxical head tilt (rare)Damage to left side of cerebellum can cause right head tilt Nystagmus = description of eye movements associated with vestibular system Move and fixation due to retina not being able to move pictures Damage to vestibular system causes spontaneous nystagmus - eyes don't stay still they drift across to one side and flick back
Describe first degree AV block
BradycardiaP wave and QRS are normalP-R interval is prolonged
Describe how respiratory mediators interact with mechanisms of bronchiolar spasm
Bronchiolar spasm / bronchial spasm / bronchospasm : sudden constriction of the smooth muscles in the walls of the bronchiolesCaused by: Irritation Recent or current infection Allergyexamples of allergic inflammation in respiratory tract :Equine and feline asthma Both inflammatory diseases Leading to bronchospasmHow does a allergic reaction lead to bronchospasm?Allergens themselves are harmless but activate T- and B- cellsActivation of B-cells by allergen leads to a type I hypersensitivity
deep digital flexor tendon
Runs deep to SDFTPasses through manica flexoriaInserts on flexor tuberosity of distal phalanx of each functional digitPalmar nerves innervate SDFT and DDFT
management of hypoxia and hypercapnia
Capnography Hypoventilation, hyper/hypocapnia, etCO2, approximate PA of carbon dioxide in alveolus and arterial bloodBlood gas analysisCan measurePaCO2PaO2Blood pHElectrolytesLactateOthersPulse oximetry - tells saturation of haemoglobin with oxygenWhatever the cause increase the oxygen supply
normal ECG = s wave
S wave - first negative deflection after R waveVentricular depolarisation at base which is last
Radial nerverootsmuscles suppliedcutaneous supply
C7, C8, T1Extensors of the elbow, carpus and digitsCraniolateral surface of the forearm and dorsal surface of digits (not digit in horse)
Median nerverootsmuscles suppliedcutaneous supply
C8, T1Flexors of the carpus and digitsPalmar surface of manus (and dorsal digit in horse)
Ulnar nerverootsmuscles suppliedcutaneous supply
C8, T1, T2Flexors of the carpus and digitsCaudal surface of forearm and lateral manus (and dorsal aspect of digit in horse)
VQ mismatch summary
Can be altered by positioning and different pathologiesBottom of the lung is described as an area with high perfusion and at the top low perfusion (as blood passes that due to gravity) Therefore positioning is very importantVentilation and perfusion becoming unevenly spread when standing - lots less perfusion in dorsal lung and lots more in area below thatWhen there's a diffusion abnormality : often caused by blockage between capillary and alveolus so oxygen unable to diffuse ultimately leads to hypoxaemia
angiostrongylus vasorum
Can be called heart worm. Adults live mainly in pulmonary arteriesLife cycle indirect : dog is definitive and slug is intermediate host
Outline the coagulation cascade in secondary haemostasis
Can be deficient in any of these factors and they will have varied impacts, depending on the effect.
When considering cardiac function, which index is more important for perfusion of peripheral tissues - cardiac output or blood pressure?
Cardiac output will reduce blood flow to lungs Perfusion is the passage of fluid through the circulatory system or lymphatic system to an organ or a tissue, usually referring to the delivery of blood to a capillary bed in tissue.
What can be observed in a cardiac radiograph?
Cardiac silhouetteGeneralised enlargement.Individual chamber enlargement- left and right atrium, left and right ventricleChanges in great vessels
growth of the primitive tube
Cardiac tube grows quicker than other parts of embryoSO it begins to foldFalls to right this is called d - looping Can fall to left abnormally l-looping
spine palpation
Careful palpation along the spine should be performed to identify any consistent areas of resentment which could indicate pain.
catalase tast
Catalyses the decomposition of hydrogen peroxideHelps protect cells from oxidative damage by reactive oxygen species (ROS)
Outcome of thymic education
Central toleranceT cells which don't react to body's own peptide antigens are selected - negative selectionHuge T cell diversity in peptide recognition T cells recognise any non self peptideMaturation of T cells
Describe the anatomy of the ventricular system including sites of production of CSF and routes of flowwhat is CSF?
Cerebrospinal fluid: fills cavities, is formed by dialysis of blood in choroid plexus within 3rd and 4th ventriclesproduced by by ultrafiltration of plasma and active transport35% - lateral ventricles23% - Fourth ventricle42 % elsewhere
What is the physiological mechanism by which a cough is produced in airway disease?
Chemical or mechanical stimulation of cough receptors in the pharynx, trachea, main carina, branching points of large airways, and more distal smaller airways causes a nerve impulse to travel via the vagus nerve to a cough centre in the medulla. This then generates an efferent signal via the vagus, phrenic and spinal motor nerves to the expiratory muscles to produce a cough.
DDSP - dorsally displacement soft palate
Choking down - gurglingLoud expiratory gurgling noise diagnosed by endoscopy and nasal occlusionSeverely reduces VO2 max
What is the name of the structures producing cerebrospinal fluid?Where in the ventricular system are these structures situated?
Choroid plexusIn the lateral, third and fourth ventricles
what disease processes can cause effusion in the thorax?
Chromosome abnormalities, heart conditions, lung problems or abnormal lymph drainage, cancer, haemorrhageChylothorax or pyothorax
clinical signs and diagnosis oslerus osleri
Chronic coughSometimes wheezingExercise intolerance, dyspnoea or deathImmune response to adults in trachea and bronchi causes the worm to encapsulateTrying to contain itThis causes nodulesDiagnosis - bronchoscopic diagnosis : ch. Ch nodules can be seen particularly at the tracheal birfurcationL1 in faeces on in BAL fluidResolution of tracheal / bronchiole nodes may take several weeks post treatment
defence of lungs = trapping
CiliaNasal passages to bronchiolesThey moved coordinated and symmetrically towards the pharynxMucusMucoid gel layer which the tips of the cilia touchAqueous sol layer coves the ciliaAntibacterial lysozymeMucocilary escalator =Mucus producing cellsGoblet cellsProduce viscous secretionForms a gel layer over the solPresent in nasal, tracheal, bronchial epithelium not terminal bronchiolesSubmucosal (subepithelial) glands Contain serous secretion Neck of gland opens at epithelial surfacesClara cells In alveoli serous mucin
left ventricle
Circular in section occupies all of apexProminent papillary musclesAorta is central
what are the clinical signs, diagnosis and treatment of oestrus ovis (sheep/goat) = bot fly
Clinical signsAvoidance behaviourExcess nasal dischargeLaboured breathingLoss of appetiteMay induce non-localised symptoms due to secondary bacterial infection - lung abscessDiagnosisELISA testVisualisationTreatmentNitroxinyl, moxidectin (sub-cutaneous), Ivermectin
Crenosoma vulpis (fox lungworm)clinical signs, diagnosis and treatment
Clinical signsInfection may be sub clinicalGaping - birds open mouth and extended neckWeight lossDiagnosis - eggs (containing larvae) in faeces/adults in trachea following post mortemTreatment - flubendazole, mebendazole and fenbendazole
what are the clinical signs, detectio and treatment of dictyocaulus arnfeldi
Clinical signs : eg persistent cough and not responding to certain drugs eg antibioticsDetection - broncho-alveolar lavage/tracheal wash may reveal worms and large numbers of eosinophilsTreatment : ivermectin, fenbendazole, moxidectin
what are ganglion
Collection of nerve cell bodies in peripheral NS with same functionsynapses, cell bodies, general swapping of nerve fibres(train station where you see lines coming into central station and coming out are other nerves / swap train lines - ganglion is the train station)
outer ear
Collects sound wavesPinna - elastic cartilage and skinQuite mobile in animalsExternal acoustic meatus - (external auditory canal)L shaped tube ending in ear drum and contains sebaceous glands that produce ear wax - acting as barrier to infectionTympanic membraneEar drum/tympanumCovered by epithelium on outside and mucus membrane on inside
corneal opacities
Corneal oedemaEndothelial dysfunction eg endothelial dystrophy, intraocular inflammationEpithelial dysfunction - corneal ulcerFluid enters stromaRegular arrangement of collagen fibres disrupted Cobblestone opacityEndothelial dysfunction : oedema more opaque/diffuse
examining the tear film
Corneal reflectionSchirmer tear test to measure test production
cranial and caudal air sacs of birds
Cranial air sacs Cervical, clavicular, cranial thoracic Connecting to ventral bronchiCaudal air sacs Caudal thoracic, abdominal Connecting to primary bronchus Connected with pneumatic bones Involved in evaporative heat loss Help with sound production
caval syndrome in Pulmonary Hypertension and D. immitis / narrowing of pulmonary artery
Critical conditionLarge number of worm burden in the right atrium and posterior vena cavaIncreases venous pressure damaging liver parenchymaIncreases cholesterol content of erythrocyte membranes leading to fragility and haemolysisSevere anaemia - many immature/nucleated red blood cellsErythrocyte haemolysis leading to haemoglobinaemia (free haemoglobin in blood) and bilirubinaemia (bilirubin in blood) and haemoglobinuria - (blood in urine)Dog may collapse/die
What is the Bursae function?
Cushion tendons in high risk areas by distributing pressure
what happens in the response to haemorrhage in blood vessels
Increased sympathetic tone to vesselsStimulate vasoconstrictionResults in increased systemic vascular resistance and therefore moves the MAP back to normalAlso local endothelial responses
fate shunt 3 : ductus arteriosus
DA is a big muscular conduitPatency is maintained by low pO2 and high PGE2First breath increases pO2, PGE2 cleared, DA constrictsBlood flow in opened lungs: pressure lower in lung and higher in the body, also helps to close the DA, but can take a while for full closureRemnant called ligamentum arteriosum
Canine heart worm
D. Immitis - affects cardiac/pulmonary system and can be potentially fatal in dogs/catsEctopic migration and infection can occur even in natural hostEctopic - affects unusual locations or unusual/unnatural hostAccumulated water sources are very important for mosquitos which are the carriers of infection
spinoreticular tract
Deep pain and visceral sensationsNot as defined as other pathwaysprimary afferents in spinal cord diverge cranially and caudally spreading out over segmentsallows intersegmental reflexes such as withdrawal responsesecond order afferents in dorsal horn project to reticular foramenthen pass to thalamusactivates limbic system - emotional response
Name the bacteria which are responsible for causing footrot in sheep
D. nodosus and also F.necrophorum
key differences in bovine and canine
D.viviparus - mixed Th1/Th2 but elevated Th2 cytokines as well as increased IgEand eosinophilsA.Vasorum deposits of immunoglobulins - IgA, IgG, IgM complement C3 and fibrinogen can be seen in the lungs of infected dogs during the acute phase of infection
Describe the initial response in primary haemostasis
Damage to blood vessel endotheliumLocal neural reflexes (pain receptors)Muscle contraction (direct mechanical impact on smooth muscle cells)Thromboxane A produced by activated plateletsSerotonin released (δ granules)=> Vasoconstriction and reduced blood flow
What happens to cardiac output in heart failure?
Decreased cardiac outputDecline in the stroke volume that is due to systolic dysfunction and/or diastolic dysfunctionLoss of contractility which can be caused by alterations in signal transduction mechanismsVentricles can become less compliant and 'stiffer' which does not allow diastole
decreased vascularity
Decreased vascularity: under-circulation results in lung fields more radiolucent- right to left shunts, pulmonic stenosis or tricuspid dysplasia resulting in under-circulation of lungs, hypo-volaemia.
defence of lungs = antimicrobial compounds
DefensinsPieces of amino acids produced by macrophages, neutrophils and epitheliumThey are attracted to the microbe and are embed into the membrane and form a poreKills bacteria, fungi and enveloped virusesLysozymeIn mucous they are antibacterial enzymes They break down bacterial cell walls
Transposition of the great vessels
DescriptionThe two main arteries leaving the heart are reversedEffects on cardiac functionIn transposition of the great arteries, the positions of the pulmonary artery and the aorta are switched. The pulmonary artery is connected to the left ventricle, and the aorta is connected to the right ventricle.Oxygen-poor blood circulates through the right side of the heart and back to the body without passing through the lungs. Oxygen-rich blood circulates through the left side of the heart and directly back into the lungs without being circulated to the rest of the body.Clinical signsTransposition of the great arteries symptoms include:Blue colour of the skin (cyanosis)Shortness of breathLack of appetitePoor weight gain
gas transport
Diffusion due to differences in partial pressuresHaemoglobin affinity for oxygen, carbon dioxide, and hydrogenCarbon dioxide content for deoxygenated blood is higher than oxygenated blood
Describe the mechanisms of vasodilator drugs
Dilate arteries, veins or both. Break the vicious cycle of heart failure.Act by reducing arterial blood pressure- afterload, reducing venouspressure- preload. Reduction ofload and therefore cardiac workClinical uses- treatment of cardiac failure, antihypertensive agents.
Describe the non-specific treatment of cardiomyopathy- dilated and hypertrphic
Dilated- contractility failure of heart muscle. Drugs that improve contractility= positive inotropes- Digoxin (digitalis glycosides), Pimobendan ("Vetmedin"), Dobutamine- mimics sympathetic NS.Hypertrophic/restrictive (cats)- heart fills poorly. Drugs that helpheart relax= positive lusitropes- calcium channel blockers- quite ineffective, diltiazem- reduces Ca entering cells, reduces contractility, verapamil, beta blocker- propranolol, atenolol.
Differentiate between different wing shapes and their purpose
Dinosaurs and birdsGrowth plate are the same as dinosaur growth plateSemi-lunar carpals both have - so fold their forearms/wings the same wayNo carpal flexion - carpal abduction and adductionDimples on bones where feathers are attachedAlular - essentially birds thumb which smooths air flow over wing if angle is sharp
aeulurostrongylus abstrusus
DirectDefinitive host (cats), intermediate hosts (snails/slugs) and paratenic host - rodents, birdsDiagnosis : larvae in faeces and in BAL fluid, radiograph of the lungTreatment - fenbendazole, ivermectin, levamisole
drug elimination by metabolism and excretion
Drugs metabolised eg by liver and thus inactivated and then excreted Drug can be occur oxidation or conjugation making it inactive Makes them hydrophilic More likely to be eliminatedSome drugs directly eliminated by kidney in the urine eg penicillin
doping drugs -- anaemia and performance enhancing
EPO - increases oxygen carrying ability of bloodInhibits hypoxia inducible factor (HIF) prolyl hydroxylase Positive regulatory protein for EPO gene expression At high [O2], HIF prolyl hydroxylase targets HIF for destruction Erythrocythaemia - increases red blood cell production
what is happening with a dog with severe bleeding
Effects of hypovolaemia on CV function, sensing an altered blood pressure, neurological response mechanisms, effects on heart/vessels, RAAS, local responsesPreload - decreasedStroke volume - decreasedMAP - decreasedViscosity - won't changeTissue oxygen delivery - compromised
virus replication
Eg RetrovirusViral entry Enters via multiple different methods Bind to specific receptor on cell surface Virus enters the cellReverse transcription in retrovirus - RNA to DNA copy DNA then traffics the nucleus and gets integrated into nucleusTranscription to RNA Which can be used to make more genome or more proteinViral assembly and release
calcium channel blockers
Eg Verapamil and DiltiazemBlock voltage-dependent L-type Ca2+ channels in cardiac muscle and vascular smooth muscleGeneral effects on the cardiovascular system Antidysrhythmic effectsSlows conduction, reduce contraction force and causes coronary vasodilation Reduces myocardia ischemia in humansAllow the heart to fill better and increase blood supply to the heart itselfSVT, feline HCM
investigations of anxiety:elevated plus maze test
Elevated plus maze-testThe anxiety of the mice comes from aversion directed against open spacesWe can make conclusions and objectify the emotionsAnxiolytic drugs eg benzodiazepine increased the time spend on open edgesControlled conditions allowThe study brain mechanism of anxietyStudy genetics of anxietyDevelop anxiolytic drugs
modifications for hoof / horn
Elongated dermal papillae is formed at coronary band by basement membrane and dermisBasal cells make keratinocytes - which become squamesGlued together keratin squames - form tubulesTubules fluted together by intertubular horn - form hoof/hornHoof slides over/between dermal lamallaetake 12-15 months for hoof growth from coronary band to ground surface
eosinophils in Pulmonary Hypertension and D. immitis / narrowing of pulmonary artery
Eosinophils - important in parasitic and allergic disease they migrate from blood into tissueIncreased numbers occur in blood and tracheal washes (BAL) during cardiorespiratory parasitism - eosinophiliaGranules large and small cause damage to parasite surfaceHow does the eosinophil degranulate?Fc receptors on eosinophils allow them bind to parasites coated in antibodies and once bound they degranulate.Antibody mediating relationship between nematode and eosinophilEosinophil begins releasing granules
layers of the myocardium
Epicardium Visceral pericardium Blood vessel adventitial layerMyocardium Cardiomyocytes Contractile part of the heartEndocardium Continuous with blood vessel lining
blood components
ErythrocytesPlatelets (thrombocytes)Leucocytes (white blood cells) Granular leucocytes - granulocytes Neutrophils Eosinophils Basophils Non-granular leucocytes - agranulocytes Monocytes Lymphocytes T-cells (70-80%), B-cells (10-15%), NK cells (5-10%)
Why does packed cell volume increase?
Erythropoietin is produced by interstitial cells in the kidney primarily due to hypoxaemia - which can be caused by ascent to altitudeReleased into the circulation and triggers the development of red cell precursors in the bone marrow and release of immature and mature red cells - can increase the PCV by up to 25%PCV increases in 3-5 days and stays increased for the stay at altitudeIncreases oxygen carrying capacity of the blood - goodCauses blood to be thicker and flows less efficiently through already 'diseased' capillary beds and uptake and delivery of oxygen from the lungs is reduced - bad
what happens once the neural folds and grooves form?
Folds fold and meet in the middle very first developedHole at one end and the otherFusion occurs in cervical region and proceeds in both directions the tub zips up towards head end and tail end (like a raincoat with two zips)Ultimately the neural tube is formed
nutrition of lens
Fetus - lens is supplied by tunica vasculosa lentisAdult - no blood vessels and no nerves, aqueous humour = supplies oxygen and glucose
Describe the process of haemostasis
Fibrin clot removal:Tissue plasminogen activator (tPA) activates plasminogen to form plasmin.Breaks down fibrin fibres to fibrinogen degradation products (FDPs)- the smallest of these are called D-dimers, FDPs act as anticoagulants by interfering with platelet aggregation and fibrin polymerisation.Feedback loop to prevent the continuation of secondary haemostasis
the laryngopharynx
From intrapharyngeal opening to opening of oesophagus and larynx Contains epiglottis of larynxIntrapharyngeal opening : formed from free edge of soft palate and palatopharyngeal archesCommon pharynx - between soft palette and epiglottis
what are the seven bones of the neurocranium?
Frontal boneParietal boneInterparietal boneTemporal boneEthmoid bone (cant see from outside)Occipital bone (back of skull)Sphenoid bone (base of the skull)
vitreous humour
Gel between lens and retinaLargest ocular structureTransparentAvascular and nerve-free (lens + cornea also avascular)99% water, 1% protein/cellsFunctions Shock absorber Removes waste products Maintains intraocular anatomy
4 sections of neurological exam
General examinationHead and cranial nervesTrunk and spineLimbs
Describe the dimensions of the heart in this radiograph:
Generalised enlargement- trachea pushed up, wide cardiac silhouette
explain the role of pineal gland in biological rhythms?
Gland attached to dorsal tectumProduces melatonin and plays a role in circadian and seasonal rhythmsFound immediately behind thalamusProduces melatonin from amino acids
explain the difference between graded potentials and action potentials
Graded potentials are brought about by external stimuli (in sensory neurons) or by neurotransmitters released in synapses, where they cause graded potentials in the post-synaptic cell.Action potentials are triggered by membrane depolarization to threshold.
what are example of microbial PAMPs that can elicit an inflammatory response
Gram negativeLPSFlagellumPeptidoglycanCpG DNA motivesLipopeptidesGram positivePeptidoglycanLipoteichoic acidFlagellumCpG DNA motivesLipopeptides
growth time and temperatures
GroupTemperatureRough growth timeDermatophytes252-4 weeksAspergillus species371-4 daysYeasts (pathogenic)371-4 daysDimorphic hyphal251-4 weeksDimorphic (yeast)371-4 weeks
describe how bacteria grow
Growth is by binary fissionColonises form on plates as piles of bacteriaSome bacteria are so motile that they do not form colonises as they spread too thinlyBacteria have generation times- how often the divide or double- doubling time- the length of time required for a single bacterial cell to divide into two daughter cells.Average bacteria double every 20-30 minutes to give colonises in about 12-24 hrs (e.g. Salmonella and E.coli), but some bacteria grow slowly and can take months to form colonies (e.g. Mycobacterium bovis). It will take at least a few days to obtain a culture result.
interventricular septum
Growth of ventricle moves it to central positionOnce atrioventricular and truncobulbar cushions forms and fuseLast step is formation of two ventricles from common chamberHypertrophy of bottom of ventricle growing up towards the AV cushions
Name 5 environmental factors that alter bacterial growth rate
Growth rate- a measure of how rapidly bacteria grow in the exponential phase.pHTemperatureOsmolalityAtmosphereNutrients, e.g. glucose
What changes occur in heart rate, venous return, total peripheral resistance, tissue fluid volume and urine output after major haemorrhage? (Hint clinical example in Sjaastad, Hove and Sand). How are these changes regulated?
Haemorrhage is a clinical syndrome resulting in a decreased blood volume caused by blood loss which leads to reduced cardiac output and perfusionBelow 40% mean arterial and pulse pressures falls and heart reate increasesFall in total peripheral resistanceReduction in tissue fluid volumeIncreased urine??
self peptide
Healthy cells MHC groove is filled by a peptide generated by the cell
alveolar leucocytes
Healthy lung : macrophages, lymphocytes, occasional neutrophils, low level of mucusDiseased lungs: macrophages, lymphocytes, frequent neutrophils (neutrophilia), hemosiderophages (alveolar macrophages that have ingested and digested red blood cells), excess mucus / secretions
Describe the radiographic appearance of a heart with feline cardiomyopathy
Heart can't fill effectively- atria get bigger. Big atria on top of smaller ventricles. 3 IC spaces- too big.
how to take a sample for a ABG - arterial blood-gas
Heparinised syringe, dorsal pedal, lingual, auricular and a femoral. You see a quick flash back in the syringe and syringe will start to fill with blood. Can be done with a needle or a cannula
archicortex
HippocampusFunction - memory generation in particular spatial memory
In what direction will blood flow across the following structures in an adult? Persistent foramen ovale
Hole in between the left and right atria of the heart which allows the blood to flow from left to right atria
Describe the correct use of cattle foot trimming equipment
Hoof knives are used to trim cattle feetThe hoof knife is dragged down over the sole of the foot slowly and carefully to peel off the sole of the hoofMore of the hoof is trimmed off at the toe compared to the hoof due to the density of the hoof being greater than the toe - this ensures that the limb does not become lame and remains at good angle to the ground
Erythropoetin (epo)
Hormone that controls the rate of erythrocyte production Can be used as an enhancement drug in sportsThe source is : early embryonic/foetal/early neonatal life = expressed in yolk sac, liver and kidney (also spleen and bone marrow)Adult life it is produced in the kidney in the renal institium
piston - pendulum theory
Horse and dog take one breath per stride due to compression and opening of the lungsCan only breathe when all feet are off the ground
Crenosoma vulpis (fox lungworm)
Hosts = foxes, wolves, coyotes, raccoon dogs and badgersTarget sites = trachea, bronchi, bronchiolesLife cycle = indirect and transmission requires ingestion of molluscs as intermediate hostsEggs are excreted in the faeces they are kept inside the egg shell all the development to L3 + will occur in the egg shellThe bird will have three different possibilities of acquiring fox lungworm:Ingestion of egg with stage L3 larvaeL3 from paratenic host containing larvaeTransport hostPenetrate duodenum wall reaching blood stream/liver before travelling to lungs and trachea and then eggs are produced and swallowed - cycle continues
control of pituatary glandendocrine/neuroendocrine?
Hypothalamus driving activity of pituitary glandAnterior pituitary is outside the BBB - can receive feed back from periphery easilyNeurosecretory cells (neurons) project to vascular bed in anterior pituitary
what happens when arterial pH has gone down ? How do we evaluate what has caused this?
If arterial pH has gone down hydrogen ion has increasedIs it acidemia that is respiratory or metabolic in originWe answer this by looking at the carbon dioxide and carbonate values and decide which has deviated from normalDeviated carbon dioxide : respiratory, deviated carbonate : metabolic
Describe the radiographic appearance of alveolar pattern in the lungs
Ill-defined, "fluffy" increased opacityPresence of air alveologramsPresence of air bronchogramsLobar margins may be seenBlood vessels, heart and diaphragm obscuredlike a fog - cannot see outlines of structures
keratoconjunctivitis
Inadequate tear productionSTT < 15mm/minCommon in toy breeds eg cocker spanielLocal immune-mediated destruction of orbital and Nictitans lacrimal glands - body attacking the glandsCorneal ulcersAnatomy of superficial versus deep ulcersCorneal wound healingCorneal opacitiesClinical signs: Conjunctivitis, thick mucoid discharge Blepharospasm/squinting Corneal ulceration Corneal vascularisation and pigmentation Reduced vision
propanololB1 and B2 adrenoreceptor anatonist- noradrenaline
Increase in heart rate is massively reducedBeta 2 and beta 1 could be in the heartUnlikely to be any alphas in the heartPropanolol (b1 and b2 adrenoceptor antagonist): Isoprenaline
sympathetic action at SA node
Increased activity causes releases norepinephrine at SA node Increases heart rate Increases rate of drift to threshold This works by the activation of -adrenergic receptors
Clinical signs of listeria, prevention and treatment
Incubation period of neural Listeriosis ranges from 14 to 40 days.Dullness, circling and tilting of head facial paralysis.Unilateral facial paralysis can result in drooling and dropping of eyelids and ears.TREATMENTIn early stages with antibioticsHowever once damage has be done there are limited options for repair so severe cases are PTS.PREVENTIONDo Not feed poor silage to pregnant ruminants.Do not feed poor quality silage at allEnsure feed method used reduces ocular contact.Vaccines do NOT work as the pathogen is intracellular.
non self peptide
Infected host cell MHC groove is filled by a peptide derived from pathogens proteins
how can microbes cause disease
Infection :Colonise or invade tissuesMicrobe may produce toxins and poison the hostAssociated with infection but sometimes just ingestion of pre-formed toxinMicrobe cause a reactionAllergic reactionCombination of above
main role of complement
Inflammation Stimulate histamine release from mast cells (mast cell degranulation)Chemotactic agents Recruitments of neutrophils and macrophages to site of infectionCell lysis Through pore formation in cell membranes - including bacteriaOpsonisation Coating of surface area leading to increased phagocytosis
corneal vascularisation
Inflammation of conjunctivaBlood vessels growing inOnce ulcer healed the blood vessels hypo perfuse - sort of go awayComplex interaction of proteases, growth factors, cytokines, epithelial cells, stromal keratocytes, inflammatory cells and lacrimal glands
canine c3 deficiency
Inherited disorderIncreased susceptibility to infectionHave no serum C3 - 126mg/ml in normal animalsHave trouble in making antibodies against certain pathogens - E coliIncreased pyometra, pneumonia, sepsis
Porcine Factor H deficiency
Inherited recessive autosomal diseaseFactor H stop C3B activationC3 accumulates on basal membrane and damages kidneyNo availability for C3 in serumDie of anaemia and renal failure
indirect cholinergic antagonists
Inhibiting the enzyme that usually metabolises Ach in the presynaptic cleft - acetylcholinesterase (AChE)Chlorine is reuptaken more ACh available at the receptors. - These drugs have the added cholinergic effect of improved skeletal muscle tone & strength
photoreceptor function
Inner segment and outer segmentPigments that pick up and trap light in pigmentCurrent runs across channel Light hits channel Sodium channel closes becomes negative and then hyperpolarisation occurs
process of breathing
Inspiration muscles contract Thoracic volume increases By contraction of diaphragm and intercostalsAir flows from the atmosphere into the lungs Until the alveolar external pressure differential has been eliminated = brief pauseProcess of expiration is reverse passive process
anatomic remnants
Internal umbilical arteries atrophy - become round ligaments of the bladderInternal umbilical vein redundant - becomes round ligament of the liver
Two components of internal intercostal
Interosseus - part of muscle that is between the bone portion of superior and inferior ribs (depresses and retracts the ribs)Interchondral - elevates the ribs (joints formed between the costal cartilages of the ribs)
entropion
Inversion (inward turning) of all parts of the eyelid marginReally common particularly in dogs and certain breedsTreatment - remove an ellipse of skin and stich up or an injection of eyelid filler
nystagmus
Involuntary movement of the eyeball, often referred to as 'dancing eyes'
Outline the distribution of H2O within the body
Intracellular fluid (ICF) compartment- 2/3 of total body H20 within the cells.Extracellular fluid (ECF) compartment- 1/3 total body H20, 80% interstitial fluid- between cells and blood vessels, 20% blood plasma- circulation.
laryngeal musculature
Intrinsic muscles - between laryngeal cartilages and they are involved in respiration and phonationExtrinsic muscles - connect the larynx to hyoid bones, pharynx and sternum and they are involved in swallowing
Cranial nerve XII= Hypoglossal test
Intrinsic muscles of the tongue and pharynxDoes the tongue have patent muscle fibresDoes it feel firm under finger tips
Atlanto - Occipital joint
Joint between condyles of occipital bone and cranial articular fovea of atlasC1 and skull (atlas)The upward an downward movement / dorsal and ventral flexionYes joint
where are the sympathetic ganglia located?
Just ventral and lateral to the spinal cord the chain extends from the upper neck down to the coccyx
What is haemostasis?
Keeping the balance of blood flow in the body, a balance between abnormal bleeding (haemorrhagicdiathesis) and hypercoagulability (thrombosis). A complex sequence of physical and biochemical changes induced by damage to tissues and blood vessels.
negative control
Known not contain the biomolecule of interest and adds validity to any positive resultsIt will show if any solutions of the assay are contaminated
examining the cornea
Light source +/- magnificationDarkened roomLooking for : irregularities, opacification, vascularisation, pigmentationFluorescein staining Orange dye that turns green in alkaline tears Adheres to and stains hydrophilic tissues such as exposed corneal stroma Useful for corneal ulcer diagnosis
Which chamber of the heart is enlarged in this cardiac radiograph:
L Heart Enlargement- DV: main stem bronchi split at level of LA-will move their positions.
Describe the location of the heart structures in a radiograph
LA- left auricular appendage. Left atrium cannot be seen.
narcolepsy
Lack of orexin (function) destabilises the sleep waking flip-flop and emotional stimuli (amygdala) can induce sleep
long axis and short axis view
Long axis view : from base to apexShort axis view : across heart
what is the spleen and its function
Largest lymphoid organAttached to greater curvature of the stomach on left side of abdomenFunctions :Storage of bloodDestruction of old red blood cellssmooth muscle capsule (allows contraction to allow excess blood into circulatory system), trabeculae, central arteries, red and white pulp
long axis view of the left ventricle
Left sided structure further away from probe
Describe the differences in the great vessels of the heart in the horse compared to the dog
Left subclavian artery branches off the brachiocephalic trunk rather than the aorta.The left and right common carotid arteries branch later off the brachiocephalic trunk resulting in a section of the brachiocephalic trunk called the bicarotid trunk.
what is the structure of the avian herat
Left ventricleThick walledForms entire apexContain muscular bars on interiorRight ventricleThin walledValves = left AV valve, right AV valve - muscular flap, no chordae tendinea
Describe the vertebral heart scoring system
Length (L) is measured on lateral vs no number of vertebral bodies (starting at the cranial edge of T4). Width (W) measured similarly.Vertebral heart score (VHS)= L+WAverage in dogs is 9.7 (range 8.5 - 10.5), 8 in cats.
What is and where does endochondral ossification occur?
Length growth in long bonesCartilage is invaded by vessels and undergoes mineralizationOccurs in the growth plates
lens subluxation
Lens movingCrescent shape at topParticularly common in terriers - with acutely painful eye - anterior lens luxation Normal flow of aqueous humour Pressure inside eye increases rapidly causing acute secondary glaucoma
accommodation in avian vision
Lens shape Softer lens shape = facilitates more rapid accommodation as it quickly changes shapeCorneal curvature Independent process in each eye Iris sphincter - striated muscle so under voluntary control
where are the ganglia located in parasympathetic
Long ganglia lie close to the organ they supply and there is no chain or ganglia = preganglionic nerve fibresShort fibres run a short distance from the ganglion to the organ = postganglionic nerve fibres
Filaroides hirthi and F. milksi
Live in the terminal airways, bronchioles and alveoli in dogsUsually asymptomatic, although coughing and dyspnoea may occurLife cycle : direct, and infection occurs via ingestion of L1sVery easily transferred in kennels because larvae are infectious when passed out through facesDiagnosisDetection of L1s or embryonated eggs in faecesRadiographic exam may show a diffuse interstitial or focal nodular pattern
Dipetalonema reconditum
Lives in subcutaneous tissueWe need to distinguish between D. reconditum microfilariae from D. immitis microfilariae in heartworm endemic regionsSignificance probably in false positive D. immitis results. Acid phosphatase test determines species - bipolar stains in D. immitis and entire body in D. reconditum
basophils and eosinophils histology
Lobulated nucleusBasophils - granules are blue (like the nucleus)Eosinophils - granules are orange-redFeline eosinophil partially rod shaped eosinophilic granules
blindfolding test in horses
Making it hardCan cause a head tiltAllows diagnosis as makes diseases eg vestibular more obvious
type of nuclei in hypothalamus and their functionParaventricularSupraopticSuprachiasmaticLateralVentromedialArcuateMammillary
Manufacturing oxytocin and ADHOxytocin and ADHBiological clockCircadian rhythmArousal/feedingFeedingEnergyMemory
enriched media
Medium which contains the nutrients required to support the growth of a wide variety of organisms and encourage bacterial growth
What parts of the brain stem control the cardiovascular system?
Medulla oblongata (myelencephalon) which is the lower half of the brainstem continuous with the spinal cordContains the cardiac, respiratory, vomiting and vasomotor centres - regulating heart rate, breathing and blood pressure
What are virulence factors?
Molecules which allow bacteria to adhere, invade, evade host defence, cause tissue damage, replicate or persist in the hostvirulence gene A gene encoding a virulence factor
What virus interactions can have dramatic effects on host cells?
Morphological- lysis, rounding and detachment from surfaceFunctional- inhibition or stimulation of cell divisionBiochemical- activation of cell signalling pathways, induction of immune responsesImmunological- display of virus molecules on cell surfaceThese interactions are essential for virus replication and spread.
intraceerebellar communication
Mossy fibres = excite stellate cells are inhibiting Purkinje cellsClimbing fibres = excite Purkinje cells (one to one basis)Both fibres excite cerebellar nuclei
what is virus tropism
Most viruses can only infect a specific cell types for instance skin cells or respiratory cells - this is the virus tropism
Adaptive immune responses in respiratory tract
Mucosa - exposed to potential pathogensAntibodies All classes except IgM Mucosal synthesis of IgA Diffusion of IgG from serumLymphocytes Circulating in blood and interstitium which can be recruited to the RT epithelium and lumen Intraepithelial lymphocytes are associated with mucosal membrane Rapid response
flagella
Multi-component protein tailsFilament is made of subunitsIt is powered by a proton motive gradient across the membraneDifferent bacteria have different patterns of flagellaNot all bacteria have flagellaEssential virulence component for a number of pathogens
neonatal sepsis in foals
Neonatal sepsis in foalsOne third of foal mortality is caused by bacterial infectionRecovery depends on severity and manifestation of infectionEarly recognition and intensive treatment requiredEarly diagnosisTreatment of primary disease processSupportive care
main factors that affect vasoactive tone
Nitric oxide Sodium nitroprusside, glyceryl trinitrate, via cycling GMPCalcium channels Calcium channel blockersAngiotensin II ACE inhibitors, agonists, G proteinsProstaglandins Prostaglandin mimetics, PG antagonists
parasympathetic action
No effect on ventricular muscle cellsStrong antisympathetic action on atrial cellsActs on SA and AV nodes:SA node : decreases rateAV node : slow conduction and lengthen refractory periodRate falls - negative chronotropic effect - decrease in force of contraction, negative ionotropic effect
factors influencing ventilationalveolar surface tension
Occurs at interface between water and air - air in the alveoli meeting fluid film surface of alveoliInner surface of alveoli lined with fluidReduced with production of surfactantSurface tension will stop the alveoli from being able to expand so muchSurface tension increase in smaller spheresLaw of Laplace states the pressure inside an alveolus determined by surface tension of lining fluid (T) and the radius of the alveolusPressure in smaller alveoli is higher than that of the largerConcentration of surfactant is higher in smaller alveoliSurfactant disrupts surface tension
Cranial nerve III - oculomotor nerve test
Oculomotor nerve IIIMotor to extrinsic muscles, ciliary body, levator palpebrae muscles Control of size of pupil and motor function to upper eyelid
normal sinus rhythm (NSR)
Originates in the SAN It has an inherent pacemaker rate of 70-160bpm in the dog, 160-240bpm in the catP waves are usually positive in lead IIPR interval is usually consistent from beat to beatQRS complex is usually 'normal'Rhythm may be regular or irregular
Explain why some birds can fly and others can not
Ostriches, emus, cassowaries, rheas, and kiwis can't fly. Unlike most birds, their flat breastbones lack the keel that anchors the strong pectoral muscles required for flight
optic nerve
Part of CNSConsists of axons of ganglion cells3 regions: intraocular portion (can be viewed) retrobulbar portion in orbit and intracranial portionAfferent pathway to visual cortexPasses through lamina cribosa at posterior globe: sieve like area in sclera, weak point can be damaged by intraocular pressureMyelinated or non-myelinated which changes the appearance of the optic disc
tapetum anatomy and function
Part of the choroid that lies behind the retinaRetina is translucent like tissue paper so tapetum can be seen underneathShiny reflective layer like a mirrorResponsible for eye shine at nightFunction - reflects light rays so retina receives light twice
collapsed schnauzer
Partial pressure of oxygen of 86 - normal rangespH is a little low - academicIs it carbon dioxide or bicarbonate Carbon dioxide dropped down by about ten And so has the bicarbonateWe have a metabolic acidosisUrine has glucose in - diabetic keto acidosis crisisAnion gap was larger than it should be (15-17) addition of unmeasured acid to the schnauzer blood
what are PAMPS
Pathogen associated molecular patterns - pathogens can express specific components which are recognised by the host as 'danger signals'
Evaluate the structures that may be affected by an injury to the sole region in horses and cattle
Penetrating foot injuries can damage : the P2,P3 and distal interphalangeal joint, it can damage the digital cushion, sole, navicular bone and navicular bursa. It could also cause damage to the tendons eg the DDFT or the common digital extensor.In a cow it could cause injury to the claws and similar structures as above - unlikely to see lameness as quickly in cattle as compared to horses
What structures of the thorax should be assessed first on a radiograph?
Peripheral soft tissue structuresAnterior abdominal contentsThoracic skeletonCranial mediastinumCaudal mediastinumDiaphragmPleural space
immunological controls to reduce and control pathogens?
Physical barrierMacrophagesDefensinsLysozymeLactoferrinComplementSurfactants
Describe the processes that lead to the formation of the platelet plug
Platelet adhesion- platelets bind to von Willebrand factor on exposed sub-endothelium via GPIb-IX-V receptor.Platelet activation- Platelets change shape. GPIIb/IIIa receptor activation- binds collagen. Release of agonists- a, b granule contents, ADP, serotonin, platelet activating factor, thromboxane A2.Platelet aggregation- primarily mediated by fibrinogen binding to GPIIb/IIIa on adjacent platelets. Enhanced by generation of thrombin- link with secondary haemostasis.=> Formation of platelet plugIn the 'normal' situation; healthy endothelial cells & platelets repel each other (negatively charged). Healthy endothelial cells produce prostacyclin (prostaglandin 2, PGl2)- inhibits platelet activation, effective vasodilator.
outer membranes of gram-negative bacteria
Porins allow diffusion through outer membraneThey are pore through the membraneDescribed as gated because they have charge and size limits
pre and post ganglionic fibres in sympathetic nervous fibres
Pre ganglionic fibres are short each nerve leads to ganglion containing cell bodies and lying close under the vertebral columnPost ganglionic fibres are long lead away from the sympathetic chain and travel towards the organ its supplies usually follow the path of blood vessels
primary disturbances of acid base pH- respiratory- metabolic
Respiratory - increased or decreased carbon dioxideMetabolic - increased or decreased bicarbonateAemia - there is a change in the pH of the ECFOsis - tends to refer to what;s going on in the tissues
how to take a swab
Prepare the swab- open packet and remove cap from sample tubeGently take the animal's muzzle and lift the head upGently insert the swab into the nares, keeping to the medial side of the naresDo not insert the swab more than a few millimetresImmediately insert the swab into the sample tube and label it.
Describe the azygous vein and the species differences
Present in all mammals, but there are species variations.Drains dorsal mid/caudal thorax and L1-L2 region since the caudal vena cava dips ventrally to go through the liver.Dogs, cats, horses = right azygous.Pigs = left (+ right sometimes) azygous.Ox/sheep/goat = left + right azygous.Left azygous enters coronary sinus.Right azygous enters cranial vena cava.
B cells
Primary Lymphoid tissues are the locations of lymphocyte development & maturationBone marrow - education and maturation of B-cellsThymusOther - species variation in B-cell maturation (Peyer's patches, Bursa of Fabricius)
examples of immunological memory
Primary immune response after initial exposureConcentration of antibody is not hugely raisedSecondary exposure to same antigenImmunological memory kicks in Activates memory cells Enhancing and speeding response of immune system Increase of concentration of antibodies Time of response is much quickerAdaptive immune system crucial in vaccination, quite slow but affect lasts
thymus
Primary lymphoid organFound in caudal neck and cranial thoracic regionsLarger in younger animals to kick start development of immune systemRegresses with age and is replaced with fat tissueVaries in appearance
what are TSEs
Prion disease: Proteinaceous infectious particle PrPUnusual disease PrP is a cellular proteinNormally exists in one shape (pN) but can misfold leading to the formation of large protein aggregatespD seems to propagate more misfolded protein which leads to brain dysfunction and fatal disease
two circulation systems
Pulmonary circulationRight ventricleDeoxygenated blood via pulmonary arteryOxygenated blood via pulmonary vein to the heartSystemic circulationLeft ventricleOxygenated blood to rest of body organs through aorta
define the conditions under which ventilation / perfusion mismatch occur
Pulmonary perfusion = blood flow to the alveoli allowing uptake of oxygen and removal of carbon dioxideAnything affecting blood flow to the lungs affects pulmonary perfusion
what are the two basic motor pathways in proprioception
Pyramidal pathwayExtrapyramidal pathwayDifference is in the complexity - extrapyramidal is more complexBoth have lower motor neuron as final common pathwayLower motor neurone are the same for pyramidal and extrapyramidalmonosynaptic reflex arc = pyramidal system one synapse between brain and muscle - motor control polysynaptic reflex arc = extrapyramidal system locomotion and posture
normal ECG - R wave
R wave = first negative deflection after P waveVentricular depolarisation from endocardium to epicardiumLargest deflectionBig positive in lead 2
• Understand what a rate is
Rate = measurementtimee.g. metres/second, miles/hourIf A = B then B = A x CC C = B/AThus rate = measurement/timetime = measurement/ratemeasurement = rate x timeA rate is any measurement over a fixed time
In what three ways can an organism react to a stimulus?
React with their own body i.e. groomingReacting with non-living objectsReact with social responses i.e. communication within a species
indicator medium
Reactant which recognises and binds to particular bacterial species and produces a result, often visible to the eye such as coloured dyeThis helps differentiating between several species grouped together
measured values in coulter principle
Red blood cells - absolute number per litreMean corpuscular volume (MCV) - the average volume of the red cells (fl)Platelets - absolute number per litreWhite blood cell counts - absolute number per litreHaemoglobin - The amount of haemoglobin in the blood (g/l)
temperature and pH affect on the curve
Reduce affinity of haemoglobin for oxygenAll of which tend to be increased in respiring tissuesHelpful in tissues doing metabolic work - right ward shift in curve - unloading of oxygen
function of the cornea
Refract and transmit light = major refractive component of eyeTensile strength - lends rigidity to globeProtection - Chemical barrier -Rich subepithelial nerve plexus - Igs and other antimicrobials in tear film - Epithelia cell desquamation- Migrating Langerhans cells and macrophages from limbus
What factors may be complicating and should be considered when preparing a therapeutic regime for a patient with heart disease/failure?
Renal failure, cushing's disease, elderly animals etc
reproduction and spore structures of fungi?
Reproduction is ComplexMany can reproduce both sexually or asexuallySporulation bodies can be used for identification in clinical samples.Spores are relatively resistant and can survive and spread infectionSpores germinate where conditions are favourable.
sampling - bronchial alveolar lavage (BAL)
Rhinoscopy for foreign bodies or distinctive infective plaquesSerology are there antibodies to suspected pathogensSampling from URT followed by Culture Microscopy Histopathology and cytology
What is cor pulmonale? What causes it?
Right heart failure that occurs without left heart failure. Caused by increased cardiac work secondary to pulmonary hypotension. a primary vascular disease seen at altitudes greater than 1500-2000m primarily due to hypoxia which is made worse by cold and exposure
function of soft tissues of distal limb
SDFT flexes digit and carpusDDFT flexes digit and carpusSuspensory ligament - supports fetlock and prevents it from dropping to lowNavicular Bursae - provides a cushion to the navicular bone and P3Digital Cushion - provides support for the limb and P3 shock absorbanceExtensor branches of the suspensory ligamentCommon digital extensor - extends digitInterroseous muscle - supports fetlockAccessory ligaments limits movement of tendon to prevent over stressing
how do neutrophils stick to surface and make progress
Selectins allow this / adhesion molecules (ICAM)-1 and (VCAM)-1Slows down cells passage - the interaction between selectin's and their receptors
Describe the indications of angiography
Selective vs non-selectiveSelective allows precise identification of chamber/vessel outlineValve disease/congenital defectsProvides definitive diagnosisLargely replaced by cardiac ultrasound (echocardiography)Put catheter into a specific chamber and inject contrast
Name the three different functions of neurons
Sensory, motor and interneurones
how do we recognise variable surface structures?
SerotypingPhage typing
neutrophil
Short livedCirculates in blood, first leukocyte migrating to areas of infection/inflammation in response to cytokine/chemokine gradientThey are phagocytic = engulfs and destroys bacterial pathogens through digestion with lysosomal enzymes
hearing in birds
Short external acoustic meatus to tympanumSong birds - 2 tympanic membranes which protect it from damageThey have no pinnaThey have feathers insteadSingle auditory ossicle - similar to reptilesRegenerate damaged hair cells unlike mammalsHearing is best - 1 to 4 kHz - some can hear higher frequency
reorganisation by folding
Sinus venosus begins to in wall of one of the atriaAtrial tissue both left and rightPrimitive ventricle and bulbis cordis start to develop and move and sit side by side = Become left and right ventriclesTruncus arteriosus - Sitting on top of the two ventricles - Divide into pulmonary artery and aorta
action potential generation in heart
Slow Na + channelsHave Na + channels that spontaneously open once an AP has finished at -65mVK+ channels closeInflux of Ca2+ speeds final approach of thresholdAP occurs after thresholdAbsolute refractory period
what causes genetic variation in viruses
Spontaneous mutation Mistakes during genome replicationGene transfer between viruses (or cell) Transfer of genetic information between two, usually related, viruses which have infected the same cell Production of hybrid genomes Recombination ReassortmentRecombinationGene reassortment Occurs within segmented genomes Simple exchange of genes can occur when two different viruses infect a cell Rapid evolution of virus variants
spontaneous nystagmus
Spontaneous nystagmus indicates a vestibular lesion.Nystagmus has a direction with distinct fast and slow phases.
Describe the properties of hydrophobic dugs/hormones
SteroidsLipid-solubleCross lipid bilayer easily- dissociates from transport proteinBind to proteins in cytosolCauses transcription and translation in the nucleus itselfLong-acting- takes a long time to work- lots of stagesSteroid hormones e.g. testosterone, aldosterone,thyroid, cortisol etc
what does stimulation of the vestibular apparatus lead to with extensor muscles
Stimulation of one side of the vestibular apparatus will also lead to excitation of extensor muscles on the side being stimulated. If a dog or a cat starts to fall to the right, the animal will extend the limbs on the right side to catch itself; also, the neck extensors will be activated and the head will be directed away from the direction of the fall.
What mechanisms are activated to restore blood pressure?
Sympathetic nervous system activation- SNS and PSNS are in balance and always changing to keep blood pressure up.Renin-angiotensin-aldosterone system (RAAS)
total peripheral resistance affecting blood pressure
Sympathetic tone leads to arteriolar constrictionOutflow to the veins is temporarily reduced and increased MAPNarrowing tube increases pressureReduces flow of blood to the veins
tendon sheaths
Synovial tendon sheaths are thin walled double layered fluid filled tubes surrounding stretches of tendonsEnclose tendons like tubes protecting them from pressure and reducing frictions
what is SIRS
Systemic inflammatory response syndrome - a systemic response to an array of severe clinical insults.
describe the roles of TLR receptors in pathogen recognition
TLR is complex and multifactorial and they recognise a wide range of microbial compounds
Describe the role of TLRs in homeostasis
TLRs do much more than just recognising pathogens:
What is the definition of a seizure
Temporary abnormal electro-physiological phenomena of the brainResults in abnormal synchronization of electrical neuronal activity from a group of neurones
Outline the areas of the distal limb that are most susceptible to trauma and explain the anatomical reasons
Tendon injury is the most likely - this is likely to be due to them being shock absorbers and a key role in the flexion of the digit so the movement of the limbThe pedal bone/sole of the foot is likely to be susceptible to trauma as it is the base of the limb and most likely to have damage due to the weight and foreign objects
zone of thermal comfort
The comfort zone is defined as the range of climatic conditions within which a majority of persons would feel thermal comfort
How does contractility of the heart change during physical exercise? How is this brought about?
The contractility of the heart increases due to the need for oxygen to be pumped around the body to skeletal muscle increasingEnables heart to be able to handle a greater pre load, empty more completelyActivation of beta 1 adrenoreceptorsThis is activated by noradrenaline being released from the sympathetic nervous system
what is the paratenon?
the loose connective tissue around the tendon
The roles of each part of conducting zone?bronchioles
The respiratory bronchioles deliver air to the exchange surfaces of the lungs. They are interrupted by alveoli which are thin walled evaginations. Alveolar ducts are distal continuations of the respiratory bronchioles.
why is discrimination of bacteria important?
understanding of disease, recognising new emerging diseases, improving the control infections, epidemiology
menace response
The menace response is a blink in response to a threatening stimulus to the eye. It is important not to create a draft or airflow as this will stimulate a corneal response.Optic nerve, cranial nerve II, visual cortex, motor cortex, cerebellum, facial nerve, cranial nerve VII = blinkAfferent nervous supply is the OPTIC nerveEfferent nervous supply is the FACIAL nerve
how do DNA probes work
The probe will bind to a complementary region on a DNA strand which allows this section of the DNA to be seen as the probe is usually tagged with a fluorescent or radioactive marker.
Give the classification of neurons as a function of the nerve impulse velocity and give example of anatomical locations.
The larger the diameter of the fibre and the thicker the myelin sheath the faster the transmission velocityIn the CNS - brain, spinal cord
mean arterial pressure (MAP)
The discharge of a volume of blood from the heart to the arterial system which cannot all escape through to the venous system before the next beat occurs - remains in the arterial system
extensor postural thrust
The dog is lifted off the ground and replaced on the tableAs the hindlimbs touch the table there should be a reflex extension of the hindlimbs which will also precipitate the dog to step backwards
olfaction process and olfactory cells
The ethmoturbinates extend rostrally from ethmoid boneCovered with respiratory epitheliumAlso contains olfactory sensory neuronesSniffing alters the normal airflow to bring the air into contact with the ethmoturbinatesolfactory cells- non - motile - cilia like structures Olfactory receptorsExposed dendrite on the mucosal surface detects chemicalsOlfactory neurones continuously renewed due to the presence of neural stem cells in the basal layerAxons collect in bundles in lamina propria
what are the neurotransmitters involved in seizures/epilepsy
The neurotransmitters that are involved are glutamate and GABA GABA inhibiting and glutamate facilitating seizures
toxins
Toxins A-B toxins - anthrax Two parts Binding and entering host cell - forms a pore or induces receptor mediated endocytosis Enzymatic activity responsible for toxicity Membrane disrupting toxins - listeria
Breaching the BBB ways - transcellular, - paracellular, - trojan horse
Transcellular Passive diffusion of small, lipophilic molecules through the BBB into the brainParacellular The transfer of substances across an epithelium by passing through an intracellular space between the cellsTrojan horse Fungus crosses the BBB as a passenger inside host phagocytes
enzyme - linked
Transmembrane elementActivates intracellular enzymesEg insulinInactive state of that receptor insulin binding causes the protein to become enzymeLots of proteins activated which causes a phosphorylation cascade in the cell
anatomy of lens
Transparent, avascular, biconvex bodyLens capsuleAnterior lens epitheliumLens fibres - nucleus and cortex
sense of smell in reptiles
Two different regions Vestibule (anterior) Nasal chamber (posterior)+/- concae or turbinalsNasopharyngeal duct Narrow duct
doppler interrogation of the cardiac valves
Typically used for cardiac valve and regurgitationBlood will from ventricles into pulmonary artery when valves are openShould be no backwards flow of blood when they're closed RegurgitationDuring ventricular contraction if we have backwards flow of blood into atria that's abnormal
Upper motor neurone lesions
UMN tracts are excitatory or inhibitory to LMNs and LMNs innervate either extensor or flexor muscles - in animals extensor muscles are stronger than flexor muscles therefore loss of UMN inhibition after a lesion can result in increased tone and reflex activity in the limbs caudal to the lesion cause exaggerated stifle extension in patellar reflex reduced or complete loss of movement- assesing the patellar reflex in horses is done by testing the ability of the horse to resist pulling on the tail type of muscle atrophy: differentiates between umn and lmn- atrophy in umn disease is due to disuse - caudal to the lesion and generally mild
tear drainage components
Upper and lower lacrimal punctaLacrimal canaliculiLacrimal sacNasolacrimal duct
haemagglutination
Used to determine the virus concentration from tissue culture isolateClumping of viruses interacting with cellsWorks as the viruses bind the receptors of individual cells linking togetherLarge number of virus particles required
production of virus proteins
Uses host ribosomesVirus proteins may also be modified by other host systemsGlycosylation can be important as it can prevent antibody binding to the virus
what is serology
Using sera from patients in assays with known antigens to show that an antibody has been generated in the patient to that pathogen. E.g ELISA assay
ventricular fibrilation
Usually terminalRhythm associated with cardiopulmonary arrest Heart rate rapid and irregular No isoelectric baselineECG is irregular and chaotic, no recognisable PQRST complexesCourse or fine depending on the degree of baseline oscillation
organisms that can cause respiratory disease
VIRUSESPrimary infections often followed opportunistic growth of commensal bacteria (pathogens)BACTERIAOpportunistic infection by commensalsFUNGIYeasts on surface causing infection plaques hyphal fungi causing primary infections
cannot get oxygen into the blood most common cause for hypoxia
VQ mismatch Most common causes for oxygen not being able to get into the blood Relates to and explains the consequence of lots of lung disease and lung damage Eg a horse on its back under anaesthetic causes problem with VQ mismatchIntrapulmonary shuntsDiffuse alveolar/interstitial disease
advantages of taking swabs
Valuable information, very quick to get the sample, easy to obtain, little impact on animal, no specialist equipment required, swabs are cheap
what is a virus?
a small infectious agent that replicates by infecting the cells of a host organism
vascular responses to hypoxiawhat is this mediated by
Vessels other than in the lungs vasodilate in response to hypoxaemia in order to try and improve oxygen supply to tissuesAdenosine = From hypoxic muscle/tissueLocal acidosis = Increased lactate of carbon dioxide - hyperpolarization of CM's due to increased potassium which reduces calcium channel opening potential allowing blood vessels to vasodilateNitric oxide = Causes vasodilation and is released from the endothelium
why is there a head tilt when we get vestibular disturbance
Vestibular spinal tract tends to connect from the vestibular nuclei to the extensors on the ipse-lateral sideInhibits the flexors on the ipse-lateral side and the extensors on the contra-lateral sideProducing natural change of toneHead tilt towards side of the lesion (left - left ear is down)
visceral layer and parietal layer
Visceral layer is epicardiumParietal layer is contiguous with outer layer / adventitial layer of the blood vessels
mid brain/mesencephalon function
Vision hearing, motor control, sleep/wake, arousal (alertness) and temperature regulationMesencephalon adjoins the pons and rostrally it adjoins the diencephalon (thalamus, hypothalamus)Partial or total obstruction of the cerebral aqueduct in the mesencephalon during development can lead to a blockage of CSF causing the ventricles to swell and brain tissue will be damaged
long term control of blood pressure
Volume and composition of blood is largely regulated by the kidney viapressure natriuresis RAASADHCapillary fluid shiftHas an almost infinite ability to excrete salt which controls ECF volume and hence BPPressure diuresis = pressure natriuresisCan control extracellular volume and blood pressure
Describe the importance of the spleen and changes in packed cell volume in oxygen delivery during exercise in the horse
Warm up releases RBC from the spleen rather than not
normals for interpreting arterial blood gas results
We have to decide if we have a acidaemia or alkalaemiaAnd decide if carbon dioxide or bicarbonate is most deviated from normal - respiratory or metabolic problem
McMaster Egg Counting methods
Weigh 1 gram of faecal sample and place into a universal container/tube.Place a known amount of flotation fluid in the universal and mix the sample by shaking.Pour the faecal slurry into sieve/ tea strainer placed over the beakerFlush known amount of flotation fluid through sieve into beaker.Swirl beaker whilst taking sample using pipette.Transfer the filtrate sample to the 2 McMaster slide chambers taking care to avoid bubbles.Leave the counting chambers to stand for 5 minutes before examination.Examine the filtrate in the filled chambers under the microscope at 4x, followed by 10x magnification.Identify and count all eggs within the engraved area of both chambers (ignoring those outside the squares).
pathology and detection of d.viviparus
What causes the animal to become so weak:Causes parasitic pneumoniaEmphysemic lung - alveoli damage
function and anatomy of sympathetic system
Whole body experienceFight or flightThoracolumbarGanglia close to spinal cordShort pre-ganglionic neuron, long post ganglionic neuron
Describe the appearance of pericardial effusion on radiographs
Whole cardiac silhouette grossly enlargedGlobular appearance and sharp marginOutline distinct as no movementSecondary signs of right-sided failureUltrasound very sensitive indicator
what is the medullary centre activated by
a group of neurones in the pontine reticular formation that release acetylcholine This release is a cholinergic action
diagnostic tests
abdominal ultrasound- check for other potential sources of bacteraemia eg infected umbilicusbiochemistry - assess the state of hydration - plasma lactate rises in septic shock
pleural effusion
abnormal accumulation of fluid in the thoracic cavity/pleural space
thoraconcentesis
also known as thoracentesis or pleural tap Thoracostomy tubes (chest tubes or thoracic drains) withdraw air or fluid from the pleural spacepreperationRight lateral recumbencyClean the space and ensure area is sterileRecognise where ribs 7,8,9 and the left chondrocostal (13) archincision Counting back three interspaces from the 7th interspace the point of skin incision for drainDrain passes through subcutaneous tunneltube enters thoracic cavity at subcutaneous tunnel at the 7th interspace- placed in the lower part of the space to avoid damage to the neurovascular bundle Lies along the lower border of the rib along the upper part of the space
hypoxaemia
amount of oxygen dissolved in blood that is free is normally around 90-100 when it falls to around 60mm Hg
bronchodilation sympathetic stimulation
b2 adrenoreceptors(Nor) Adrenaline / (Nor) Epinephrine acting as agonistRelax smooth muscle in lungDilation is increased via cAMPMain drugs for asthma and COPD
what happens in the response to haemorrhage in aortic arch and carotid sinus
baroreceptors in aortic arch and carotid sinus = recognition of reduced blood pressure as they're sensitive to stretch
discuss how the demands of performance create a predisposition to injury in the racing greyhound
bending the bones generates microcurrents sensed by osteocytes which lay down bone if there is a negative charge on compression side and remove bone if there is a positive charge on tension sidereduced stress leads to degradation of bone matrixthis causes a danger period as there is a lag time between repeated stresses and increase in strength
what is simple squamous epithelium?
best suited for passive transport across cytoplasmlittle protect - not found on surfaces of high stressfound in alveoli vessels blood vessels and body cavities
botulinum toxin
binds to nerve terminal and is very potentBlocks Ach release causing death from paralysisThis has also been used to treat local muscle spasms and fight wrinkles
main difference between mechanical and biological vectors?
biological will support pathogen multiplication and replication within their bodies
exercise - induced pulmonary haemorrhage (EIPH)
bleeding in the lungs High pulmonary blood pressureMore likely in cold environments
Define the areas desensitised by common regional anaesthesia
block sensation to structures distal of the anaesthesia palmar digital nerve block or abaxial sesamoid nerve block
pulmonary perfusion
blood flow to the alveoli allowing uptake of oxygen and removal of carbon dioxideAnything affecting blood flow to the lungs affects pulmonary perfusion
what expresses selectin and what is it?
blood vessel endothelium local to areas of inflammation will express new receptors - selectins they are integrin receptors external signals also cause leucocytes in the vessels to express integrins which bind the receptorswhat does the binding of integrin with their receptor do?slows down the leukocytes down near the infected tissue and the immobilised leukocytes reorganise their cytoskeleton (=diapedesis) - allow to move between the cells from the vessels into the tissuediapedesis : the immobilized leukocytes reorganization their cytoskeletonsthis changes the cell shape they spread out over the endothelium leukocytes pass between gaps in the endothelial cells cell migrates along chemokine gradient until reach area of inflammation
haemotoxylin stain?
bluestains mainly genetic material
Define the main divisions of the central nervous system?brain and spinal cord
brain and spinal cord
four main steps of an ECG
calculation of heart rate, determination of the heart rhythm, measurement of the complex amplitudes and intervals, measurement of the mean electrical axis
Lower motor neurone lesions
can either occur due to damage to the neruonal cell body in the CNS or due to damage to the axon in the periphery- distal to lesion both axon and neural termiantion at NMSK junction degenerate- decreased or absent reflexes due to the efferent portion of any reflex arcs involving these muscles being lost- no ACh is released and the muscle fibres will not be stimulated to contractrapid or severe muscle atrophy from denervation of muscles
The blood-gas barrier effect of exercise and training on it
can reduce or thin the blood-gas barrier in order to improve efficiency of transferThe rate of diffusion of gases depends primarily on: driving pressure or gradient ie the difference in gas pressure across the membrane, the thickness of the membrane, total area of membrane available
discuss the specific adaptations and physical attributes of racing greyhound
canine muscle fibres are primarily type I (slow supportive and aerobic) and type II (fast motility of limbs)the type II are mixed ability fibres which allow fatigue resistance and also sprintmore fat in canine muscles than horses/humans which makes them better adapted for endurance
lubventricular systole
contraction of ventriclesResults in cardiac outputAtrioventricular valves close
lamina propria
consists of loose, highly vascularised supporting tissue which becomes more condensed at its deeper aspect to form a band of fibroelastic tissue
electrocardiography
heart rate and rhythm measurement - continuous ECG
what can we ultrasound
heart, lung surface, pleura and pericardium, lymph nodes, thymus and space occupying lesions, vascular structures
metabolic acidosis
decrease in bicarbonate and pHmetabolic problemeg dog with horrendous diarrhoeacan be caused from loss of bicarbonate or gain of acid - ketones in diabetesresult acidosis, decreased carbonate and carbon dioxidetreatment : intravenous fluids and address underlying cause
histology of tendon?
dense connective tissueextracellular fibres (collagen mainly) parallel and regularly orientatedresistant to stressmany fibrocytes and fibroblasts
What does the dermatome contribute to?
dermis - skeletal muscle, dermis, muscle stem cells and brown fat cells
adaptive immunity
develops after previous exposure to a virus and is specific to that pathogen and strain
laboratory diagnosis of protozoan infection
direct microscopic examination Look at the eggs and different life cycle stages Sample collection is very important as the parasite have complex life cyclesserology Toxoplasma (pregnant women)Blood test at the first pre-natal examinationThis shows whether the women has had previous exposure and whether she is at risk = If a woman receives her first exposure to toxoplasmosis while pregnant the baby is at risk
hopping
dog is hopped sidewaysOnce the limb goes outside the line of the body there should be a rapid and accurate sideways repositioning of the limb
where are sensory cell bodies supporting large afferent fibres located?
dorsal root ganglia or trigeminal ganglion
signs of upper airway disease
dysphagia, sneezingnasal dischargeinspiratory dyspnoeaobstructed naressnoring/snortingfacial deformity
what happens in the response to haemorrhage in sympathetic effect on heart
effect on the heart - sympathetic nervous tone from noradrenaline released from nerve endings acting on beta1 adrenoreceptors in the heart Inotropic effect : increased force of contractionChronotropic effect : heart rate increases
preload?
end diastolic volume (EDV) - the amount of blood in the ventricles at the end of diastole (filling)
structure of the cornea
epithelium, stroma, epithelium
process from embryo to lining uterus lining?
funnel-like structures catches oocytemoves to top and fertilization occurdivides into two cells which divides into four and into eightmorula moves to uterus and form blastocystembryo hatcheshatching blastocyst lines uterus lining
risk factors of cardiac disease
heritable : particular bulls can produce susceptible/resistant offspring, degree of erythrocytosis (increase in RBC), chronic cold temperatures, obesity, certain plant toxins
what are the three types of cartilage?
hyaline, elastic and fibrous (fibrocartilage)
What is the cerebellum and how did it develop
highest density of neurones within the whole brainRelated to movement and posturePaired upgrowth from where pons is is attached to brainstem by 3 paired peduncles (stalks)Part of the hindbrain caudal part of cranial cavity : Dorsal to 4th ventricle
non permissive host
host in which the parasite cannot complete life cycle eg Toxocara spp. in humans
capnography
in normal circumstances metabolic rate doesn't alter much, so ventilation determines arterial CO2. Arterial CO2 therefore tells us about ventilation.At the end of the tidal volume the machine sucks some of the breath into the device and analyses the amount of carbon dioxideRelates to ventilation and heart output
What are the three main classes of cell surface receptors
ion channel / ligand gatedg protein linkedenzyme linked
neutrophilsoxygen dependent
killing after phagocytosis / called respiratory burstIncreased oxygen utilisation Generation of reactive oxygen species such as superoxide anion, hydrogen peroxide = damage bacterial membranesProduce hyperchloric acid
white matter
lots of myelin (fat) insulating nervesDorsal columns: ascending (sensory) tracts.Ventral columns: descending (motor) tracts.
central venus pressure
measures pressure of blood returning to the right side of the heartusually reflects the volume of blood returning ie is circulating volume okay
what is the main supply to distal forelimb?
median artery continuing as medial palmar artery
commensals
microorganisms which exist on / in animals without causing diseaseThey are important to the health of animals as they can : stimulate an immune response and support development of immunity, can compete against pathogens, play a role in nutrition
inverse agonist?
most receptors are in their resting state and a inverse agonist binds has more affinity to the resting state of receptor which is opposite of agonist and antagonist equally attracted to both statesThere is a equilibrium between the resting and active state but usually receptors are naturally resting
Hyphal growth
moulds form large coloniesthey can produce asexual spores in different ways
What does the myotome contribute to?
muscle - skeletal muscle
fetal lungs and livers
net receivers during foetal life, to help growth in adults, lungs liver are not 'providers' oxygen, nutrients
In a closed system when we add additional acid
no way of blowing off carbon dioxide and the animal would die as carbon dioxide would drop down
peripheral nervous system affect
non-adrenergic non-cholinergic (NANC) neurotransmitter in many tissuesThe neurotransmitter is released at same time as Ach and noradrenalinePrimarily slower response than aboveCan be either excitatory or inhibitoryCan be potential therapeutic targets
innate immunity
non-specific and rapid response against viral infection
What is chronic inflammation
normal response again but wound may not heal because of foreign body or continuing infecition takes weeks months or yearseg : persistent infection (mycobacterium tuberculosis) or foreign body
Haematocrit (Hct)
packed cell volume (PCV) - this is the fraction of whole blood volume that consists of red blood cellsCalculated Hct / PCV
choanae
paired caudal openings of nasal cavity, funnelling air from nasal cavity into nasal pharynx
where are flexor tendons located?
palmar aspect muscles arise from medial epicondyle of humerus in forelimb and caudal aspect of femur, tibia and fibula in hindlimb
where is the abaxial sesamoid nerve block?
palmar digital nerves on abaxial surface of proximal sesamoid bonesneurovascular bundles can be palpated over sesamoidsdesensitises the digit
where are the cardiac images obtained
parasternal window Left or right side of windowLateral recumbency in dogsHeart closer to chest wall when lying down due to gravity and standing in large animalssubcostal window
lacrimal function nerve tested?
parasympathetic VII can be tested by the Schirmer tear test
abnormalities
peripheral dimplingirregular lung surfacesecond image is pneumonia with pleural effusion
macrophages
phagocytosis pathogens, foreign bodies, antigen that communicate with T-cells
sodium channel blockers
physically block the pore slows down phase 0Slows down depolarisationThey reduce the maximum rate of depolarisation during phase 0LidocaineSlows AP generation and raises depolarisation threshold - used to treat ventricular tachycardiaThey are extensively used as toxins
eosin stain?
pink stains mainly proteins (cytoplasm)
sandwich ELISA
plate is coated with specific antibody to capture the analyte another specific antibody is used for detection = analyte is sandwiched between the antibodies
fundus
portion of the posterior segment of the eye that is viewed with the ophthalmoscopeTend to think of as a pizza= sclera base= sclera and choroid base and tomato= sclera choroid and retina base tomato and cheese
resting potential in cardiac muscle
positive charge on the outside and negative on the inside
what is the composition of a tendon ?
primary collagen fibres form primary bundlesprimary bundles surrounded by endotenon forms secondary bundles - crimp present surrounding secondary bundlesecondary bundles form tertiary bundlestendon is made of tertiary bundles
process of gastrulation?
primitive streak formsSome cells detach from the epiblast layer and they start to move towards the primitive streak and primitive nodeWhen they arrive they push through the epiblast and end up between the epiblast and hypoblastSome displace hypoblast = endodermSome lie between epiblast and endoderm = mesodermCells remaining in epiblast = ectoderm
keratinisation
process of differentiation of living epidermal cells characterised by high cellular metabolic activityhappens in live cells
nitric oxided and endothelins
produced locally in response to lots of stimuli they are endothelial derived factors Nitric oxide A tonic vasodilator Released by shear stress Acetylcholine or kininsEndothelins Usually vasoconstriction
rapid immunomigration (RIM)
proteins (antigens and/or antibodies) are absorbed onto a strip of tissue such as nitrocellulosesample is applied on one end of the strip and will migrate along the strip by capillary actionsample may need to be pre-treated (eg diluted) prior to application
function of the lens
provides a third of the refractive power of eye (rest is cornea)AccommodationBlocking UV light from the retina
effects of hypoxia on the pulmonary vessels
pulmonary vasoconstriction of the small pulmonary arterioles in response to hypoxia- significantly effects ventilation and perfusion opposite to what happens in response to hypoxaemia poiseuilles law - a small amount of vasoconstriction incerases the resistance within the pulmonary vasculature
hypoxaemia
reduced oxygen in the blood
hypoxia
reduced oxygen in tissues
bone marrow responsereticulocyte countHIGHNORMAL
regenerativenon-regenerative
how do we see emotions in animals?
response patterns:Motoric Movements (often seen as behavioural)Autonomic Activation of the ANSHormonal Adrenal medulla and cortexIntegrative Brain activity
negative sense
reverse complement to positive sense - does not normally code for protein
cardiac muscle?
show striations but different to skeletalpresence of one or two nuclei per cell found in centreoften branchedshorterpresence of intercalated disks (darkly stained transverse lines)
standardsied exmaination
similar to physical examination consistent measurements The more parallel you can get the better the imagineHorse - left sided views allowing us to see left atrium and aortic outflowGives us better alignment
what are the histological characteristics of smooth muscle?
simple and least differentiatednarrow spindle shaped fibressingle central nucleus per fibreno striations within sarcoplasm (cytoplasm)
four types of simple epithelium?
simple squamous, simple cuboidal, simple columnar, simple pseudostratified columnar
What is the limbic system
single cortex on top of corpus callusom projecting nuclei in the hypothalamusit receivers projections from cortex from cortex from limbic structures which particularly projects towards brain for certain behaviours eg stress response
what does ectoderm form?
skin, epidermis, nervous system
pro angiogenic factors
switch on angiogenic path
what are the three main types of junctions between neurones and other excitable tissues?
synapses= Neurone to neurone can be excitatory or inhibitory only in grey matter (small gaps in cells)neuromuscular junctions= Neurone to muscle cells, always excitatory in skeletal muscle (still have a synapse)neuroglandular junctions= Neurone to glandular cells and most secretory glands
what is atrial systole?
the atria contract and push blood into the ventricles
What are commisures?
transverse connections between hemispheres
C3a main role
triggering inflammation (C4a and C5a)Change smooth muscle contraction leading to more blood in areaIncreases vasodilation - oedema formation allowedActivates mast cells or neutrophilsIncreases fluid in the tissue and speeds up lymph flow
types of nerve fibers and their functions?
type A fibers- thickest and fastest conducting, myelinated eg skeletomotor fibrestype B fibers- medium in size, myelinated, slower than type A eg preganglionic automatic efferentstype C fibers- smallest and thinnest, non-myelinated, slowest conduction eg postganglionic autonomic efferents
structure of erythrocytes
typical lipid bilayer of globular proteins with a biconcave disc shapehave the ability for elasticity / deformability which allows passage through capillary diameters FUNCTION = transport of oxygen from lungs to cells and transport of carbon dioxide from cells to lungsswelling of erythrocytes failure of Na+ ion movement causing swelling of erythrocyte cell membranes leading to swelling and loss of the normal concave disc morphology
sandwich ELISA
used an antibody pair to detect specific antigen eg cytokines, acute phase reactants, virus particles
non-cellular
virusesPrions (Proteinaceous infectious particles). Single proteins.
identify 1-8
1 - nasal septum2 - dorsal meatus3 -4 - ventral meatus5 - common meatus6 - dorsal concha7 - ventral concha
AtenololB1 selective adrenoreceptor antagonist
Beta 1 receptor on the heart will cause increases in heart rate and contractility when stimulated
organic acids
By products or participants in aerobic metabolism, e.g. lactic acid.
carbonic acid of carbon dioxide
Carbon dioxide enters the red blood cells where it reacts with water to form carbonic acidCarbonic acid dissociates to Bicarbonate ions (transported to plasma) Hydrogen ions (buffered by Hb)
function of the iris
Controls amount light into the eyeForms part of the blood-ocular barrier
Enhancing the stride length
Limits stride rate - inertia (limbs are pendulums - the amount or force or energy that is required to change the force or energy of that pendulum) = mass x radial distance(squared)Increase limb length or by flexion and extension of backulna extends the amount of work of the triceps mediolaterally flattened thorax with scapula positioned laterally - everything is designed in a straigth line allows scapula and shoulder joint to be free to move
potassium channel blockers
MechanismSlow phase 3 of action potential and therefore increase refractory period and duration of action potential
clinical signs D.immitis
Narrowing pulmonary arteryExercise intoleranceHydrothoraxHydroperitoneumChronic coughDyspnoea
sclera components
OpaqueLargest portion of the outer coat of the eyeComposed of collagen and fibroblasts - has to be quite strong3 layers are episclera, scelra proper/stroma, lamina fuscaAnterior portion covered by bulbar conjunctiva
what do cartilage channels undergo during endochondral ossification?
Process that channels undergo as growth slows and layer of growth cartilage becomes thinnernarrower finally replaced completely by boneNormal physiological processVessels regress and canal obliterated and filled with chondrocytes which becomes cartilage
avian renal portal system
Receives blood from caudal bodyDrains from hind limbsDrugs injected into hind limbs are metabolised before general circulationPortal blood flow regulated - portal valveContinuous with caudal mesenteric vein
Myocbacterium tuberculosis
Recognised by TLR9,TLR4, TLR2 expressed on the surface of alveolar macrophagesInitiate transcription of inflammatory cytokine in order to regulate infectionReduced TLR1, TLR2 activity leads to susceptibility to M tuberculosis and M lepraeGenotyping might improve therapeutic intervention
mycobacterium turberculosis
Recognised by TLR9,TLR4, TLR2 expressed on the surface of alveolar macrophagesInitiate transcription of inflammatory cytokine in order to regulate infectionReduced TLR1, TLR2 activity leads to susceptibility to M tuberculosis and M lepraeGenotyping might improve therapeutic intervention
non-specific defences
Removal of particles Physical and anatomical G head position and cilia Lubricants Mucus Reflexes Coughing and sneezing Antimicrobial compounds Lysozyme
What drugs act on the RAAS?
Renin-angiotensin-aldosterone system (RAAS): ACE inhibitors (names end in -pril).Improves ejection fraction.Improving the oxygen supply/demand ratio primarily by decreasing demand through the reductions in afterload and preload.Prevents angiotensin II from triggering deleterious cardiac remodelling.Reduce level of angiotensin II- venous dilators, arterial dilatorsReduce levels of aldosteroneReduce fluid accumulationOverall effect is "decongestion"ACEI- causes efferent arteriolar dilation, causing a reduced glomerular filtration rate.
components of haemoglobin
Represents 95% of erythrocyte protein the components :Globin Two pairs of polypeptides 2 x alpha or 2 x beta chainsCentral haem group Containing iron atom that can bind a molecule of O2
coulter principle
Simplify and improve blood cell analysisThis meant that large populations could be screened rapidlyThis forms a size distribution plots against cell number and cell sizeComparison of different cell types
dendritic cells
Specialised group of antigen presenting cells (APCs)Many subsets according to their tissue location
withdrawal response
Squeezing the toes allows you to test two separate modalities : sensation and strength of withdrawalWithdrawal reflex is a local segmental reflex sensation and withdrawal are independent of each other except for the necessity of intergity of the peripheral nerves
what do chordae tendinae do
Stop valves prolapsing up into the atriumRupture causes failure of mitral valve to close
what are the clinical signs of a dog with a case of pleural effusion
This will decrease the amount of space that is available for the lungs to expand within the chest cavity The dog must work harder to breathe - clinical signRapid shallow breathing and increased respiratory effortDogs may have open mouthed breathing, may also cough
optimal gas exchange ratios
Ventilation should be evenly distributed and match blood supplyV/Q ratio of 1 is balanced and idealAlveolus left - obstructive bronchial = no ventilationV/Q ratio is zeroOn right - obstruction in alveoli - perfusedNo gas exchange can occur - alveoli dead space
Why would a blockage in one of the ventricular structures cause a build up of CSF in the brain?
Ventricles become enlarge the excess fluid increases the size of the ventricles and puts pressure on the brain - the blockage would cause the swellingHydrocephalus
what is MAP dependent on
cardiac output, total peripheral resistance, blood volume
what ganglion go directly to the heart
post ganglionic
what three parts is stroke volume composed of
preload, contractility and afterload
which peripheral nerve is tested by the extensory carpi radialis reflex
radial
causes of hypoxia/hypoxaemia
reduced oxygen inspiredcannot get oxygen ot lungsreduced systemic oxygenoxygen cannot bind to HB (and / or oxygen cannot get off haemoglobincannot get oxygen into the blood
what is the blood brain barrier?
selective barrier between parenchyma of nervous system and circulating blood- it selectively blocks to large molecules mainly by active transport unless they are lipid soluble
cranial laryngeal nerve (x) from vagus
sensory innervation of the laryngeal mucous membranemotor innervation of cricothyroideus
dilator muscles control
Dilator muscles under sympathetic control and we have constrictor muscles under parasympathetic controlAdrenaline when scared which causes iris to dilate to get as much light in as possibleParasympathetic constricts with too much light coming into our eye
miosis
Excessive constriction of the pupil
Major Histocompatibility Complex (MHC)
Expressed onto the cell surfaceIt relates to role in transplantation Determines if tissues/cells are recognised as self or non-selfControls how immune system detects and responds to specific antigensAntigen presentation where MHC molecules display peptide fragments for recognition by appropriate T cellstwo classes of MHC
process of lung development
Form by process of branching morphogenesis Many genes involved Lungs develop similarly to the kidneys and breast tissue
iron metabolism after RBC breakdown
Free iron is toxic to cells as it acts as a catalyst in the formation of free radicals from reactive oxygen speciesWhat happens to iron: (never allowed to be free)
the tongue worm - Linguatula serrata
Infects dogs from eating meat coming from small ruminants that are infectedCauses - mucopurulent nasal discharge, epistaxis and sneezingReported treatments - salt water flushes to detach adult and treatment with milbemycin oxime
Treatment Strategies
Inflammatory mediators act on host cells and stimulate neurones particular vagus nerve which is part of parasympathetic nervous systemCNS respiratory centre activatedHigh release of neurotransmitters acting on host cells which leads to smooth muscle contraction and bronchoconstriction
innate immune responses in the respiratory tract
LeucocytesOriginate from blood and InterstitumCarried from lung to trachea Macrophages Neutrophils Basophils Eosinophils Mast cellsNumber of molecules produced: Lysozymes Defensins Surfactants Cytokines Complement Inflammatory mediators
why is necrosis essential in development
Limb development - the interdigital mesoderm initially formed between fingers and toes is removedOssification - death of chondrocytesNervous system - death of neurones
What are the 2 subfamilies of motor neurones?
Lower motor neurones Motor neurones of the spinal cord and brain stem nuclei that innervate skeletal muscle effectorsUpper motor neurones Located in the brain and have fibres that descend to and modify the action of lower motor neuronesThe lower motor neurone serves as the final common pathway for all output to striated skeletal muscle
mechanisms limiting ventilation regionally
Lower portions of the lung are ventilated more than the upper zonesIntra-pleural pressure is higher (less negative) at the bottom of the lung (base) than at the top due to the weight of the fluidLung easier to inflate at low volumes than at high volumes (becomes stiffer) Resting lung volume at base small so expands well on inspiration
dictyocaulus arnfeldi
Lung parasite of horses and donkeys (mules/zebra)Horses more likely to be infected when kept on pasture with donkeys - donkeys will not show clinical signsDonkeys are direct hostInfection in donkeys has PPP of 13 weeksIt is found in small bronchiIn horses, not patent - very few eggs - L1 in donkeys it is a patent infection (this happens when there is direct evidence of parasite reproduction that has been detected)
fate shunt 2 : foramen ovale
Lungs open = low pulmonary resistancePlacenta gone = high systemic pressurePressure differential causes septa to close together and fuseBlood is diverted to lungs via right ventricle - the remnant is called the fossa ovalis
Cranial nerve IV - Trochlear nerve test and Cranial nerve VI - Abducens nerve test
Motor to extrinsic musclesLooking at nystagmusNormal = eyes flick from right to left as the horse locks on objectsAbnormal = wouldn't track
horses swab sites
Nasopharyngeal swabs are used for sampling pathogens in the upper respiratory tractrestraint standing physical restraint - head collar and stockstesting for steptococcus equipass it to At the level of the caudal soft palate, the swab should stimulate a swallow.
Deep gluteal
O: Ilium and ischiatic spineI: Greater trochanterA: Extend and abduct hip. Rotate medially at hipN: Cranial gluteal nerve
long axis view - left side
Plane of view is more verticalLeft sided structures are much closer to us
what do drugs affecting cholinergic transmission interfere with?
ReleaseReuptake of metabolitesFacilitation of receptorsMetabolising enzyme
parasympathetic action at SA node
Releases acetylcholine at SA node cells to decrease heart rate Decreases rate of drift to threshold
Which chamber of the heart is enlarged in this cardiac radiograph:right
Right Heart Enlargement- DV: RA only chamber in expected place.Reversed D- globular shape of right side.
alveolus
The are minute polygonal chambersDiameter changes with inflation and deflation of the lung and also varies with size of the animalTwo outermost surfaces are formed from alveolar epithelial cellsThere is a network of alveolar capillaries between the two epithelial sheetsBlood gas barrier - single basal laminaFibre skeleton - connective tissue cells and fibres form alveolar Interstitum
fixation
The fixating response can be useful in the co-operative patient to demonstrate conscious vision of a patient.Using a small slow moving object, the ability of an animal to follow its path is tested.
response to hypoxia
The normal drive to ventilation is changed readily by changes in levels of carbon dioxide in the body
Canine distemper virus spread
The virus replicates in the URT spreads to the tonsils and bronchial lymph nodesA cell associated viraemia follows with spread to other lymphoreticular tissuesViral replication produces lymphocytolysis and leukopenia resulting in immunosuppression - facilitates a secondary viraemia to developonce in neurones it can spread by neurotropic spread cell to cell
selective inhibitor
These are sometimes added to petri dishes to ensure that only the bacteria that we are cultivating are able to grow, so it kills any background bacteria which may compete for resources or obscure the results.
anisocoria
Unequal size of pupils, can be serious or of no consequence
normal ECG dog - Q wave
Ventricular depolarisationInitially at the septum down towards the apex which give the Q waveFirst negative detection after P wave
operant conditioning?
a learning procedure whereby the effects of a particular behaviour in a particular situation increase (reinforce) or decrease (punish) the probability of the behaviour
yeast cells division / budding
asexual division by budding
obligate parasite
at some or all stages of life cycle cannot survive in the absence of the host
when does gastrulation occur?
between implantation (the attachment of the fertilized egg or blastocyst to the wall of the uterus at the start of pregnancy) and organogenesis (production and development of organs)Basic body plan is established and the primary body axes are established
What is epilepsy
disease of the brain characterized by an enduring predisposition to generate epileptic seizuresUsually at least 2 unprovoked epileptic seizures less than 24 hours apartcaused by recurrent episodes of paroxysmal brain disfunctionElectrical signal sends neurotransmitter a to synapse-- so with epilepsy there's a huge surge of electrical signals and not enough inhibitors
genome
either RNA or DNA, single or double strand, circular, linear, if single stranded it can be positive of negative sense:Positive sense = sequence can code directly for virus proteinNegative sense = reverse complement to positive sense - does not normally code for protein
Cavitation
formation of cavities - holes or spaces
chromosome
haploidcircular DNAchromosome is much longer than the typical prokaryote and must be compacted to fit inside the cell To fit into the cell it is organized into a DNA-protein complex called the nucleoid.Has essential core genes of the bacteriaHas other genes that define the properties of the bacteria
oslerus osleri
is a parasitic worm with the adult worms found in the upper airways (trachea).Metastrongyloid nematode with direct life cycleInfection occurs by ingesting L1 infected faeces or by direct transfer of L1 in sputumNo gastropods are involved
Ecto-parasite
lives on the outer body, surface of the host eg fleas, lice, ticks, mites
dermis
living layer where connective tissue blood vessels and nerve
MHC class I and II
seen by cytotoxic T cellsclass 2 : to alert the t helper cells if there is an infection going on, mainly on antigen presenting cells - macrophages, dendritic cells, B cells
functional residual capacity
the volume of air present in the lungs at the end of passive expiration
explain the process of preparing a histological section - paraffin proceduce?
tissue collectionfixation (10% formalin) and trimmingdehydration (series of alcohols up to 100% to remove water)paraffin embedding - makes it rigid form block of tissuesectioning with microtomestraightening sections on water bath - float flattransferring sections to slidestaining and cover slipping - see material
secondary lymphatic tissues
where lymphocytes are activated = spleen, lymph nodes, mucosa associated lymphoid tissue
primary lymphoid tissues
where lymphocytes are produced and mature intoB cells (in the B structures)= bone marrow, bursa of fabriciusT cells = thymus
Defence of the lungs: to exclude or remove foreign agents
ØPrevent entryØSwallowØTrappingØSneeze/cough outØAntimicrobial compoundsØEliminate via immune response
plasmid
•Not all bacteria have plasmids (but they are very common)•An independent small DNA molecule (most are circular)•Has partition genes so when bacteria divide both cells gain plasmid•Plasmids can transfer between related bacteria carrying a range of properties
function of the third eyelid
- Protects ocular surface- Distributes tear film and removes debris from corneal surface- A third of aqueous production from the third eyelid gland- Contains immunoglobin secreting plasma cells - defence on ocular surface
how do viruses hack host cell machinery to increase viral protein translation?
- hijack ribosomes to produce viral proteins- dsDNA viruses utilise host DNA polymerase for replication, enhance viral production- block S phase when host cell DNA is normally replicated, block G1 phase allows for accumulation of viral proteins and vision production
how do viruses host protein block?
- host antiviral activity inhibits release of retrovirus particles- tetherin is induced by interferons, causes retention of fully formed virions on infected cell surface- viral protein Vpu counteracts this activity by degrading tethering
some limitations of ELISA
- indicates previous exposure but not sufficient to indicate when infection occurred- false negatives and positives can occur
what is the mechanism of vaccines?
- induces immunity1. host exposure to vaccine antigens2. naive T and or B cells that recognise begin clonal expansion and differentiation3. develop population of memory cells4. next encounter with same antigens induces protective secondary response
Which nerves carry somatic (motor) impulses to the muscles of ventilation?
- phrenic and intercostalIntercostal mm. supplied by intercostal nerves which are ventral branches of the thoracic spinal nerves
name three stages of dopaminergic events implicated in stereotypies?
- sensitisation of corticostrial circuits (reduced frontocortical inhibitory control)- enhanced mesoaccumbens DA responding- hyperactivity of the dopaminergic system leads to enhanced nigrostriatal transmission - behaviour rigidity
describe the path of the nasolacrimal duct and infraorbital canal
- the nasolacrimal duct opens at the nasal puncta on the ventral floor of the nasal vestibule close to the transition point between the nasal mucosa and the nostrilLacrimal duct is at the top outer edge of the eyeNasolacrimal duct allows tears to drain from each eye into the noseNasolacrimal duct ends near the lateral wall of the nostril on the medial surface of the alar fold of the ventral nasal conchaHence for nasolacrimal flushes in cattle, entry is usually through the upper of lower lacrimal puncta
ion movements during action potential
- threshold of excitation causing Na voltage dependent ion- channels in membrane to open and Na rushes in by diffusion and electrostatic pressure- depolarisation from -70mV to +40mV- K voltage dependent ion-channels open later than Na channels as they require larger depolarisation- Na channels become refractory = channels become blocked and cannot open again until membrane reaches resting potential so no more Na in- K channels open so K moves in freely out of cell causes membrane to return to normal value and K closes- sodium channels reset as membrane normal valueovershoot over -70mV before normal return eventually NaK pump remove the Na ions that leaked in and retrieve the K that leaked out
what are viroporins?
- viral proteins that make hydrophilic holes in cells, allow release of virions
what factors influence the emergence of virus infections?
- virus adaptation and change- international travel- host susceptibility to infection- climate change
How has nerve function been affected in the image below?Which nerve is affected (and muscle)What is the clinical significance of this?Roaring in horses - laryngeal hemiplegia
- vocal folds seem to be hanging into the oesophagusRecurrent laryngeal nerve damageIntrinsic muscles of larynxReduces their airflow during exercise and reduces the amount of oxygen a horse can inhale
how bacteria of different groups can have antibiotic resistance
1 enzymes that degrade or inactivate antibiotic B lactamases - penicillin/ampicillin2. Alteration of target sitealtered ribosome structure3. elimination of antibiotic from bacterial cellefflux pump - tetracycline4. bacterial cell impermeable for antibioticgram negative cell wall - penicillin
how do viruses evade the antiviral state?
- concealment (replication intracellularly, prevent antigen presenting, integrate into genome)- interference with immune system (block cytokine receptors, inhibit induction of interferon and signalling)
what is antibody detection of viral protein/antigen testing for?
- detection of viral antigens- immunoflourescence / immunohistology used for:detection of viral antigen, identify in cells or tissue by reaction with specific antibody
lymphocytes histology
9-12 micro metres in diameterNucleus round condensed chromatinPale blue cytoplasm
the oxygen pathway
= Atmosphere= Into the lungs by ventilation (tidal volume)oxygen into the blood by diffusion= Heart= Circulated to tissues in the blood= Into the tissues by diffusion Into mitochondria = oxidative phosphorylation PO2 reduces as travels through system PCO2 increases as travels through systemPartial pressure way of measuring gases - directly proportional to concentration of a gas
what does molecular epidemiology tell us
1. Identification of specific organisms2. Relationship of organisms in the environment3. Presence of specific genes in a population
life cycle of a virus
1. Invade the host, through the skin or mucous membrane2. Infect susceptible cells at cellular level (tropism)3. Overcome local defences eg innate immune response to replicate in permissive cells4. Virus assembly and spread from the site of infection often via the bloodstream to other organs Undergo further rounds of replication Exit / shedding from host in high numbers to infect other susceptible hosts to ensure spread and maintenance Routes = urine, faeces, skin, respiratory tract
Describe how cardiovascular physiology is impacted in heart disease
1. Normal systemic arterial pressure.2. Cardiac output.3. Venous pressures.All related- priority is maintenance of blood pressure- tissue and organ perfusion- require a minimumperfusion pressure.e.g. in DCM- heart contracts poorly, stroke volume decreases, as does blood pressure. High heart rate- blood doesn't fill in time, preload decreases.
How can bacteria survive host defence
1. Resistance to host defence e.g complement resistance, avoiding phagocytosis and protection against recognition by antibodies2. Active subversion of host defence e.g producing toxins or ejecting bacterial effector proteins.
what are the four steps of phage typing
1. The phage attach to the surface structures2. These structures vary slightly between different isolates of the same species3. Multiple phage are assessed for their ability to infect bacteria4. The pattern of susceptibility leads to a phage typeUses lytic bacteriophageIt identifies pattern of susceptibility of a bacterial isolate to establish its phage type (PT)
sinus arrythmia
As NSR except greater variation in P-P (or R-R) intervalRhythm is irregular but regularly soIf it is related to the respiratory cycle respiratory sinus arrhythmiaNormal rhythm in dog, abnormal in catIt is mediated by fluctuations in vagal tone and abolished by giving atropine, accentuated by vagal manoeuvres
function of the nasal cavity in birds
As air gets increasingly warmer it increases the water saturation - amount of water saturated into the air. Nasal conchae warming the air so humidifying it which helps to stop drying out the lower respiratory tractWater condenses onto the surface of the mucous membrane of nasal conchae when temperature decreases - important in removing heat from body
non true lungworm
Ascaris suum and toxocara canis = most important species
fermentation assay
Assays indicate ability to ferment different sugarsCan be changed for different sugars - lactose, fructose, galactoseAll assays are based on a pH change more acid if the sugar can be fermentedPhenol red is neutral pH at red
What should be checked during regular reassessments of patients with heart disease/failure?
Assess patient for side effects, toxicity etcDrug doses may need to be adjustedThere is rarely a standard doseRegular blood chemistries are advisableRepeat investigations if indicated- unusual to doWeighAim is resolution of clinical signs- rarely a cure, will require lifelong therapy.Therapy failure- dose too low- dose by surface area not weight? Administration failure? Absorption if given by mouth? Tachyphylaxis- the longer the drug is used, the less effective it becomes, may need to change drug. Combination therapy is common.Adverse effects of therapy:Dose too high- lean weight/fluid presenceIdiosyncratic reactionComplicating factors- renal dysfunctionCo-existing disease- liver dysfunctionEffect of combinations- polypharmacy?
indications for cardiac ultrasound
Assessment of : Cardiac chamber size Enlargement/appropriate Myocardial pathology or function Structure of function damaged Valvular function and regurgitation Doppler Most common Vascular dysfunction
Explain the functions of the lymphatic system
Assists in circulation of body fluids between cells and bloodstream- returns tissue fluid to circulationProtects body against foreign material- carries material/organisms to lymph nodesTransports dietary fats
how is perfusion affected by lung disease and cardiac function
Asthma , pneumonia, mountain sicknessCardiac function - congenital heart defect, hypovolemia, pulmonary oedemaPneumonia - blood flow passes through infected region it doesn't pick up any oxygen which mixes with normal blood and this reduces lower oxygen tension in the blood
Give the four names of neuroglia in the central nervous system and their function
Astrocytes - axon guidance and synaptic support + blood-brain barrierMicroglial cells - mononuclear phagocyteEpendymal cells - transport of electrolytes and some solutesOligodendrocytes - myelinating cells
waves in the ECG
Atrial depolarisation = P waveTends to be positive bell shaped curvePQ intervalSlightly negative Q wave - septum is depolarisingR - early ventricular depolarisationS - base of ventricular depolarisationT - repolarization of ventricles
stages of the cardiac cycle on wiggers diagram / seven stages
Atrial systoleIsovolumetric contraction-ventricles contract with no volume changeRapid ejection- of blood into the aorta and pulmonary arteries from the left and right ventriclesReduced ejectionIsovolumetric relaxation- beginning of diastoleRapid ventricular fillingDiastasis- passive filling of ventricles slows, before atria contract for active filling
formation of the valves
Atrioventricular / mitral and tricuspid valvesThey form from reshaping and tissue loss within ventricular wallsThe ventricle dilates, walls hypertrophy, trabeculation occurs and endodermal cell deathThe strands of cardiac well mesenchyme from atrio-ventricular cushions which connect to ventricular wall which forms the cusps of the AV valves and chordae tendinae
muscarinic antagonist
Atropine In the heart it blocks the vagus effect (which slows the heart down) therefore the heart will increase GI motility inhibitedclinical use : tachycardia and anaesthesia to reverse heart block due to increased vagal activity Anticholinesterase poisoning - enzymes that metabolises ACh
b cell receptors
B cell transform from immature state into B cell with immunoglobin or antibody on surface membraneB cell receptor if on membraneIf It is floating it is antibodyB cells are precursors of plasma cellsImmunoglobulin secreted by plasma cells has specificity for one antibodyB cell receptor = surface immunoglobulin (Ig)
Describe the nutrition for bacteria
Bacteria require nutrition from the immediate environment, which may be a wound, intestine, blood etc.Bacteria can be fastidious- require specific supplements, or non-fastidious- grow from basic chemicals.Most vet relevant organism's pathogens are chemoheterotrophs- use organic chemicals as sources of energy and carbon.
normal ECG - T wave
Base line of ECG line is at zero and then ventricles repolarising after pauseVentricular repolarisationT wave very variable = may be positive, negative or biphasic
what are the approaches to reduce risk to infection in animals?
Basics of cardio-respiratory parasite control Optimal control Avoid risky behaviour Improve hygiene and nutrition Cover transmission cycle- proper disposal of faeces Treatment intervention
Describe the course and names of the major blood vessels providing blood supply and drainage of the spinal cord and brain, including a comparative knowledge in the major domestic species
Basilar artery- continuation of the ventral spinal arteries, both vertebral arteries merge hereInternal carotid- Dog and human only supply is internal carotid that comes up directly from common carotid- Sheep and cat are supplied from maxillary artery- Cow supply comes from maxillary and vertebral artery
Describe the vagus nerve's widespread course and the distribution of its important branches
Below the base of the skull the vagus nerve gives off branches that go to pharynx and larynxGoes to :A pharyngeal branch - to pharynxThe cranial laryngeal nerve - to larynxvagus nerve continues caudally and joins sympathetic trunk at cranial cervical ganglion which forms the vagosympathetic tract
manipulation of bronchial tone to reduce airway resistance
Beta 2 agonists and M3 antagonists act on the autonomic nervous system and can be used to reduce airway resistance.Examples of beta agonists : epinephrine, isoprenaline salbutamol or clenbuterol (more selective than adrenaline) and muscarinic antagonists : atropine (not as selective), tiotropium or ipratropium
isoprenaline - a beta adrenergic receptor agonist - B1 and B2 binds
Beta receptor in the heart and when stimulated cause heart rate to contractdon't know if B1 or B2why is there a decrease in ABP?Must be beta receptors in the vascular which are causing vasodilation decreasing blood pressure
How does the stay apparatus work?
Big hock allows the quadricep the patella up and in a medial direction so now the ligaments sit either side of the trochlear ridgeStifle held in extensionTrochlear - pullyPatella slides in groove - pull over to side sits with everything lockedMedial rotation of patella to pull it up and over to the side - lockedPull up with quadriceps and lateral movement of that to slide the patella back down to go to the grooveQuadriceps pull up on stifle and release from hook
which T cells are retained relate positive and negative selection to sniffer dogs- diagram
Bit like training a sniffer dog - identify specific drugs and ignore everything elseT cells which recognise the body's MHC class I or II are retainedKeep all T cells which recognise - positive selectionT cells which respond to self peptides in the MHC are eliminated - T cells which ignore self peptides are retainedDogs that recognise luggage with drugs in but not dogs that get excited by all the luggage
complications in diagnosing feline D.immitis
Blood smears may give false negative as no microfilariae in bloodDiagnosis may be improved by analysing samples acquired in eveningNocturnal periodicityMay have very low worm burdens - ELISA will be false negativeTherapy does little help to the catELISA used in dogs may not be sensitive enough for catsCats there are very few worms which may cause significant pathologyThe ELISA developed for use in cats measures antibody to parasite rather than parasite antigenPositive antibody serology results may not tell you current status Blood antibody will be present in cats which have previously been infected Difficult to differentiateLevel of antibody doesn't correlate with level of infectionResults should be interpreted with caution and with clinical signs
cutaneous trunci reflex
Blunt object onto muscleWe want a twitch responseRemoves flies - evolutionaryLocalises lesions = where we lose the reflex
location of B-cell maturationspecies variationhumanbirdsruminants, dog, pig, horsesrabbits
Bone marrowHuman, primates, rodents, birdsBursa of FabriciusBirdsIleal Peyer's patchRuminants (cows, sheep), dogs, pigs, horses, maybe secondary to bone marrowAppendixRabbits
erythopoiesis in the adult
Bone marrowSinusoidal capillaries with larger intercellular gaps to allow passage of cellsInactive marrow is replaced by fat (yellow marrow) but can regain activity by extension from active tissue and from circulating stem cells
b cell maturation diagram
Bone marrow, lymphoid progenitor cells go to B cell and T cellsSome B cell maturations in peyers patches of bursa of fabriciusWhich then migrate to lymphProgenitor T cell migrates to thymus for T cell education and central tolerance before migration to lymph nodes
What is the difference between central and peripheral vestibular disease?
Both display ataxia, gait disturbance and strabismusPeripheral lesion: head tilt towards side of lesion, horizontal or rotational nystagmus with fast phase directed opposite to lesion, facial nerve paresis same side as lesion, Horner's syndrome possible on same side, no postural deficits, normal mental state, no signs of cerebellar deficits.Central lesion: head tilt towards either side, horizontal, rotational or vertical nystagmus with fast phase to either side (head position may alter this), cranial nerves V, VI, VII, IX, X, or XII might be affected to same side as lesion, Horner's syndrome rarely seen, postural deficit possible on same side as lesion, depressed stuporous of comatose status, possible signs of cerebellar deficits (dysmetria or intentional tremor).
inspirationboyles law
Boyles law: P1V1 = P2V2∆P is produced by increasing lung volume (V).Increase in volume = decrease in pressureThe thoracic cage expands and lung volume (V) increasesThe expansion is brought about inspiratory muscles
Describe second degree AV block
BradycardiaP wave not conducted through the AV nodeP without QRS
Describe complete (third degree) AV block
BradycardiaPersistent failure of conduction through the AV nodeSAN is still working which is why there are many P wavesVentricles are paced from a ventricular originWide and bizarre complexes form
T. gondii and toxplasma life cyclein which host does sexual and asexual reproduction of T.gondii parasite occur
Bradyozoites are released in the gastrointestinal tract when the wall is digestThey then penetrate the small intestinal epithelium and start sexual reproductionBradyzoites and sporozoites, from cysts and oocysts respectively, are released in the intestine and infect the intestinal epithelium where they replicate - asexual reproduction by endodyogeny (budding) producing 8-16 tachyzoites. Tachyzoites are lunate in shape, about 6 microns in diameter and possess the ability to multiply in almost any cell type.
Describe the radiographic appearance of bronchial thickening
Bronchi become more prominent, may be calcified.Normal left, thickened right.Bronchial calcification- may be long term chronic changes- asthma etc. Much brighter than normal.
Describe the radiographic appearance of bronchial pattern in the lung
Bronchial opacity more prominent and extends more peripherallyBronchi appear as 'doughnuts' viewed end-on and 'tram lines' side onPulmonary vessels may be lost in the increased opacityMany causes (not only chronic bronchitis)
bronchus on radiographs
Bronchus end on appears circular and smaller circles- vessels.Side on view of bronchus- train-track appearance
Explain the tests which assess primary haemostasis
Buccal mucosal bleedingtime (BMBT)- time taken for bleeding to stop after making a small incision. A quick test to perform in practice. Requires practice and does not determine cause of abnormality. Healthy dog: 1.7-4.2 min, healthy cat: 1.0-2.4 min=> Prolonged in suffering disorder of primary haemostasis.Platelet count:- EDTA sample, counts should be performed as soon as possible to avoid clumping. Three methods can be used:HaemocytometerAutomated cell count- more accurate BUT cannot see what is happening (e.g. cat platelets tend to clump; CKCS dogs have larger platelets) therefore must check on a smear.Blood smear- estimated count from a blood smear= no. x 15 x 109/L, healthy dog/cat >10 platelets / 100x oil immersion field- check for clumping in feathered region (pseudo-thrombocytopenia).17.
bulbar vs palpebral conjunctiva
Bulbar conjunctiva overlines the sclera white with small vesselsPalpebral conjunctiva is pinker
Fish eye anatomy
Bulbous eyesDome shaped corneaRigid iris where the lens protrudesRetina adjust position of photoreceptors in the eyeDifficult to adjust to light changesPupil is fixedFocus : change lens position not the shape of the lensRatio of rods to cones varies in environment eg deep sea fish (more rods in dark)Colour and UV light visible
List the differences in structure and function between the distal limb of carnivores and herbivores
CARNIVOREShave relatively short, multipurpose limbs, used for both locomotion & apprehending prey.Carnivores gain speed by exploiting trunk flexibility to extend limb reach and thus stride length.Trunk flexibility is enabled by the small volume of viscera associated with a meat diet, which is why multipurpose limbs are required in the first place.Because trunk flexion/extension requires massive abdominal/epaxial muscular effort, carnivores are short distance sprinters.Equine limbs are particularly specialized for distance locomotion, relying relatively more on passive bone/ligament linkage and less on active nerve/muscle interaction (see details below.)OMNIVORESHave relatively long limbs that are devoted entirely to locomotion (ungulate animals have hooves). Because a roughage diet and bulky abdominal viscera limit trunk flexibility, stride length is obtained by limb elongation in ungulates. Stride rate is increased, anatomically, by reducing mass at the distal limb and, physiologically, by flexing distal joints during limb forward protraction.In contrast, ungulates are designed for distance running.
limitations with diagnosis of canine lungworm
CBC. Some other diseases will give similar resultsSmears and concentration tests. Microfilariae may not be seen if few are present. In both tests, occult infections are not detectedEchocardiogram. May be difficult to interpretRadiology. Signs may be similar to other diseasesELISA. Only adult female antigens detected. False negatives occur if - immature females present or male only infection (or problem with kit)
Compare and contrast species-specific differences between cow, sheep, goat, and pigExplain the functional adaptations in the four species cow, sheep, goat, and pig
COWTwo main metacarpal bones 2 and 3 and 4 acts as a dewclaw = fewer digits means faster movement increased stride rateSHEEPOnly two digits very similar shape to the horseAgain will increase stride rate as less digit contact on the groundSheep need to be fast animals to escape predators so that's why they have long legs and only a few digits on the groundGOATgoats are more agile than sheep and are very good climbers - two digits like sheep They are also able to forage better compared to sheep which are grazersMore pointed clawPIGFour digits only missing the first metacarpalPigs tend to dig more than cows and forageThey have more metacarpal than the cow which allows weight baring across more bones
factors influencing ventilationresistance to flow in the airways
Calibre of Airways - sizeSame factors as resistance to flow in blood vesselsResistance to flow inversely proportional to the 4th power of the tube radius = implications - radius decreases then the resistance to the air flow will increaseMouth breathing nearly halves the airway resistanceMechanisms to overcome resistanceAt each bifurcation there is increase in number of parallel branches - bronchi to bronchioles to alveoli = small diameter tubes but lots of parallel branches compensates for increase in resistance total resistance declinesLung volume increases elastic fibres within lung pull to expand tube diameterActivation of smooth muscle can increase airway diameter - muscle curves around respiratory bronchioles relaxation of muscle decrease resistanceTurbulenceAirflow pattern is turbulent or laminarTurbulent air flowVortices - swirlingRises with increasing flow speedThe flow rate is fastest in trachea and long bronchiLaminar air flowParallel movement of air, minimal frictionSmaller bronchioles, bronchi
main MSK adaptations in dog
Can survive adverse conditionsLocate prey and stalk and catch themEquipped to kill prey
main MSK adaptations in the cat
Can survive dry conditionsCan locate small prayAbility to stalk and catch preyEquipped to kill prey and defend territory - marking, signalling and fightingMuscle - fast twitch type II fibres for speedFlexibility in joints for postureLight body frameLong limbs and tail for balance with a flexible neck
haematogenous spread definition?
Cancer cells known as circulating tumour cells acquireThe ability to penetrate the walls of lymphatic or blood vessels after which they are able to circulate through the blood stream to other sites and tissues of the body
what do bacteria need
Carbon Such as glucose in order to build sugarsNitrogen Media mixtures of peptides and amino acids Peptones contain phosphate, sulphate, potassium, magnesium, calcium and ironPhosphates Part of nucleic acids and compounds with energy rich bondsSulphates Sulphur containing amino acidsMg, K, Ca, Fe Important co-factors in a number of enzymes and processesTrace Elements Certain co factors can also be essential
blood flow into atria before birth
Caudal vena cava entry into atria lots of blood entersAimed at septum primum to the left keeping foramen ovale openBlood flows right atrium to left atriumwe don't want it flowing into the lungs because they are not aerated yet Goes from LA to LV, aorta, body gets reoxygenated in the yolk sacSmall amount goes to aorta through the ductus arteriosus
life cycle explained of tongue worm - linguatula serrata
Causes irritation to the dogsDogs sneeze and causes inflammation - epistaxisThey lay eggsCoughing up the eggs will be swallowed and ingested will be eliminated in faeces of dogIngested by sheep which is intermediate hostLarvae with migrate to different organs into pupae in viscera= infectious nymph in pleural tissueRaw offal fed to dog - is how the dogs are infectedHumans can also be infected by raw meat from sheep and goat
dictyocaulus viviparus - bovine lungwormlife cycle
Causes substantial economic lossEggs will hatch whilst passing through gastrointestinal tractContaminate the manureLarvae have stagesPre patent period - 3 weeksA term of waning use for the "silent" period between the time an exogenous agent (specifically, a parasite) impacts on a living organism and its detectability in the new host
name the openings in the diaphragm for?caudal vena cava
Caval Foramen - lies within the central tendinous region of the diaphragm and contains the caudal vena cava
caval syndrome treatment
Caval syndrome surgery removalIn very heavy infections adulticide treatment may lead to severe pathology as dead worms may cause thromboembolism - obstruction of a blood vessel by a blood clot that has become dislodged from another site in the circulation.Prognosis is very poorWorms need to be removed very quickly
orbit purpose
Cavity within skull that encloses the eyePurpose: Protection, Separates the eye from the cranial cavityForamina within walls of orbit Pathway for blood vessels and nerves to reach eye
T lymphocytes (t cells)
Cell mediated adaptive immune responseRecognise antigen displayed by major histocompatibility complexRange of subsets = t helper cells, cytotoxic T cells
difference between classic and operant conditioning?
Classical is about a response that is not under the control of the organismStimulus - stimulus learningMaking the connection between the two stimuli as response is already thereOperant involves a voluntary, controllable responseStimulus - response learningConnection between stimulus and response and the response is feeding back and reinforcing the connection
variable in CSF = turbiditynormal finding change due to bacterial infection?
ClearA measure of the degree to which water loses its transparency due to the presence of suspended particlesSimilar to above
clinical signsdiagnosis and life cycle of eucoleus (capillaria) boehmi
Clinical signsSneezingRhinitisNasal dischargeEpistaxis - blood from the noseDiagnosisRhinoscopically on the epithelial lining of nasal turbinatesLifecycle unknownEggs are used in diagnostic stage have been found in dog faeces by faecal flotation and from nasal swabs/flushEggs are confused with whip worm - Trichuris vulpis and another lungworm - E.aerophilusHow to tell the differenceE.boehmi egg has rough pitted surfaceE.aerophilus egg has shell with striationTrichuris vulpis egg has a smooth shellTreatment = ivermectin and antibiotics
Cadiac GlycosidesExplain indication for use of cardiac antidysrhythmic agents
Clinical useManagement of supraventricular (atrial) arrhythmiasManagement of heart failureCardiac glycosides have a narrow therapeutic indexCan cause rhythm disturbances
clipping
Clipping May be required but may not be appropriate Have to obtain consent Water / surgical spirit with contact gel may be sufficient
tricyclic antidepressants
ClomipramineProduces more noradrenaline-NA reuptake inhibitorAntidepressentInhibits serotonin and noradrenalineThey block the reuptake of serotonin and norepinephrine in presynaptic terminals, which leads to increased concentration of these neurotransmitters in the synaptic cleft.
risk factors that predispose development of pneumonia eg calves
Close confinement - stressed and closer to spread diseaseTransportation and other stressPoorly ventilated and overcrowdingDecline in maternal antibody = more susceptibleIntercurrent infections
defence of lungs = swallowing
Close proximity of air and food passages in the head which allows swallowing easily of foreign particles which are then destroyed by stomach acidNasal CavityWithin the nasal cavity there are cilia which move towards the larynxLarynx/pharynx/glottisEpiglottic cartilage covers glottis preventing food and liquids entering larynx and trachea
the phosphate buffer system
Closed systemActive in bones important buffer in ICF and urinePhosphates as buffers - inorganic : high concentrations intracellular, especially in skeletal muscle cells
function of the eyelids
Closure for protection from traumaBlinking roleDistributes tear film - provides nutrition and hydration to ocular surface Drains till film pumps tears into nasolacrimal canaliculi Physical removal of debris from ocular surfaceContributes to tear film Mucin - goblet cells of palpebral conjunctiva (inner most layer of tear film) Lipid - meibomian glands
Explain the tests which assess secondary haemostasis
Coagulation tests:Group tests- test for groups of factors:Anticoagulant = sodium citrate (citrated plasma)- bounds Ca2+, doesn't clot until Ca2+ is added- fill tubes to line! Important!Prothrombin time (PT) or OSPT (US: one-step prothrombin time)- add thromboplastin (@ TF) and Ca2+ ions to activate the extrinsic pathway.Activated partial thromboplastin time (aPTT)- add reagent to activate the intrinsic system (surface activator & phospholipid) and Ca2+ ions- note no thromboplastin.Time to clot formation prolonged by alterations of factors (<30% normal), always get a reference range for the machine
competitive antagonism
Competitive antagonism requires a higher concentration of the agonist when the antagonist is present to ensure that the desired effect occursParallel shift of dose response curve in present of antagonist - competitive antagonism
non-cellular components of innate immune system
ComplementCytokinesLactoferrin Produced by epithelial cells of the mucus membrane and neutrophils Iron binding protein - particularly abundant in milk Anti bacteria Deprives bacteria of iron - which is essential for bacteria growth Direct damage to bacterial membranesAcute phase proteins Produced in liver in response to cytokines It is a diagnostic marker in inflammation
resistance to host defence
Complement resistanceO antigen polysaccharide chain which are very long This hinders binding of complement to the chainCapsule Incorporation of sialic acid inhibits complementAvoiding phagocytosisCapsuleM protein (streptococcus)Production of Fc-binding proteins to prevent interaction with Fc-receptors on phagocytesProtection against recognition by antibodies
photoreceptors = rods and cones
Complex specialised cellsContain visual pigments Where light energy is converted to a nerve impulse (phototransduction) ie start of process of visionCones Colour vision Visual acuityRods Night vision
outline the role of complement in innate immunity
Complex system of 30 plasma proteinsCirculates in blood as inactive precursors Available all the time activated in response to infection causing a cascade reaction It is a rapid amplification of activated proteinsC3a and C3b - acts as a sort of glue to allow immune cells to catch victimsC3 convertase forming c5 convertaseMembrane attack complex - proteins anchor themselves in bacteria membranesVirus travel from cell to cell - completely defenceless complement attaches
positive control
Confirms if the procedure is performing as intended. A positive control allows for confidence in the diagnostic test results, confirms that negative results are accurate and assists in any protocol adjustments or optimizations that may be necessary
neuropathology disease categories
Congenital anomalies (malformations)Trauma/vascularInflammationDegenerationNeoplasia
anatomy of conjunctiva : conjunctival surfaces
Conjunctival fornixBecomes bulbar conjunctiva till it reaches the corneaReflected over the third eyelidAnother fornixReflected up to palpebral conjunctivaSingle sheet with several blind endingsForeign bodies can be trapped in fornix
functions of the larynx
Connection of nasal part of pharynx and tracheaBreathing / respirationProtection of lower airwaysSwallowingFormation of voice - phonation
Annulus fibrosus
Connective tissue sheath that electrically insulates the ventricles from the atria - ossificationAllows ventricular filing to complete before the initiation of ventricular systole
regions of brain involved in menace response
Conscious visual pathwaysContralateral visual cortexContralateral motor cortexIpsilateral cerebellar hemisphere
limb evaluation
Consists of a number of tests to assess several different modalitiesResponses vary between animals and so comparison between sides and from front to back can be useful to determine the significance of your findingassess the proprioception, sensation, segmental reflexes, muscle mass and tone
nasal conchae
Consists of turbinates covered by nasal mucusCoiled up like a paper roll very thin boneDivide the airways into three different areasVentral, middle, dorsal
anatomy of ciliary body
Continuation of posterior aspect of irisForms uveal part of iridocorneal drainage angle - where the aqueous humour drains out the eyeDouble layer of epithelium continuous with irisComprises - smooth muscle, connective tissue, blood vessels, nervesPars plicata = folded part- ciliary processes where the lens muscles attach and secretes aqueous humourPars plana = flat
three types of capillaries
Continuous Continuous lining of endothelial cells Found in majority of the bodyFenestrated Not true holes but rather when the cell membrane is compressed to permit greater fluid transmission Found in glomerular capillaries in the kidneysDiscontinuous sinusoid Wider intercellular gaps permit increased exchange with surrounding tissues Found in liver, bone marrow, lymphoid tissues and some endocrine glands
automated cell counters
Coulter principle (electrical technique) : to enumerate/counts and identify blood cell populationsA stream of cells passes through an aperture between two chambers, across which there is an electrical currentPassing cells disrupt the electrical flow which causes a pulse to be recorded:Amplitude is proportional to cell volume and pulse frequency = cell number
Which nerves control laryngeal function?
Cranial laryngeal nerve has two branches. The internal branch innervates the mucosa and the external branch innervates the cricothyroid muscle and constricts the pharynx.Caudal (recurrent) laryngeal nerve innervates the intrinsic muscles of the larynx (except the cricothyroid muscle).
ductus venosus
Creates low resistance pathway through liverShunts through the liver with quite a high rate of flowFrom umbilical vein to caudal vena cavaUmbilical arteries (x2) : go to placentaUmbilical vein : go to the fetusDV allows 50% blood to bypass liverDV streams blood to foramen ovaleclosureFunctional closure in minutes this is due to improved pulmonary clearance and no umbilical blood supply, anatomical closure within minutes
right ventricle
Crescentic in section and wraps itself around the left ventricle it is cranial to it and to the rightPulmonary artery is cranial to and left of aortaTrabecula septumarginalis - within the right ventricle which is a muscular band
The only muscle that widens the glottis
Cricoarytenoideus dorsalisSupplied by recurrent laryngeal nn. Relevant for left laryngeal hemiplegia Left nerve is damaged Inspiratory noise Poor performance Can feel the wasted muscle Fails the slap test
Poiseuille's Law
Cross sectional area is related to flowReduced diameter (Æ, from 4mm to 3mm) increases resistance by 4th power (i.e. 1mm × 2 × 2 × 2 × 2 = a 16-fold increase in resistance)..so blood flow reduces massively
innervation of the larynx
Crosses two segments so it has two nerve suppliesCranial - laryngeal nerve from vagus providing lots of sensory innervationCaudal - laryngeal nerve from cranial nerve XI - accessory and innervates all the laryngeal muscles
laboratory diagnosis of fungal infection
Culture Used for distinguishing between moulds and yeasts Morphology different - look different Dermatophyte Test Medium (DTM) plate Very difficult to determine Dermatophytes should have a red 'halo' early in its growth Any fungus will turn the plate red if left too longDirect microscopic examinationHistopathological demonstration of fungal hyphae or yeast forms Ringworm hyphen
Describe the consequences of different injuries to the sole region in horses and cattle
Damage to sole - lameness difficulty to workDamage to navicular bursa - synovial fluid leak and meet with red blood cells which will affect the distal interphalangeal joint as the synovial fluid acts a lubricant for the jointThe DDFT provides flexion of the digit and shock absorption of the horse and flexes the distal phalanx which would not be able to do if the damage occursSuspensory ligament damage will cause damage to the suspension of the pedal bone and the stability of the fetlock joint
primary causes of acquired heart disease
Degenerative valvular disease = Aortic/mitralHeart muscle disease - cardiomyopathyValve/endocardial infectionPericardial diseaseRate/rhythm abnormalities
microhaematocrit for dehydration, jaundice, haemolysis, lipaemia, lukocytosis
Dehydrated - plasma low also an artefact of stored blood - swelling of RBCsIf the plasma is not clear this can be a sign of diet or a sign of jaundice where the liver function is effected creates a very yellow plasmaIncrease in white blood cells increased buffy coat can be signs of leukemia
hypovalaemia
Dehydration is the loss of fluid from the ECF and ICFHypovolaemia is loss from vasculatureHypovolaemic shock is loss of enough vascular fluid to cause inadequate oxygen delivery to the tissues
enveloped viruses
Derive envelope from cell membranes by budding - they can bud from these components: Plasma membrane = Influenza, retroviruses Nuclear membrane = Herpesviruses Internal organelles = CoronavirusEnveloped viruses are less stable than non-enveloped
gram positive
Describing the group of bacteria that have a cell wall that is structurally less complex and contains more peptidoglycan than the cell wall of gram-negative bacteria. Gram-positive bacteria are usually less toxic than gram-negative bacteria.
Aortic stenosis
DescriptionWhen the heart's aortic valve narrows. The valve doesn't open fully, which reduces or blocks blood flow from your heart into the main artery to your body (aorta) and to the rest of your body.Effects on cardiac functionCongenital heart defectCalcium build up on the valveRheumatic feverClinical signsAbnormal heart sound (heart murmur) heard through a stethoscopeChest pain (angina) or tightness with activityFeeling faint or dizzy or fainting with activityShortness of breath
Pulmonary stenosis
Description condition in which a deformity on or near your pulmonary valve narrows the pulmonary valve opening and slows the blood flowEffects on cardiac functionPulmonary valve stenosis usually occurs when the pulmonary valve doesn't grow properly during fetal developmentWith each heartbeat, the valve opens in the direction of blood flow — into the pulmonary artery and continuing to the lungs — then closes to prevent blood from flowing backward into the heart's right ventricle.Clinical signsHeart murmur — an abnormal whooshing sound heard using a stethoscope, caused by turbulent blood flowFatigueShortness of breath, especially during exertionChest painLoss of consciousness (fainting)
What is the effect of temperature on bacterial growth and what are the names of bacteria at different optimum temperature ranges?
Different bacteria have different optimal growth temperatures, as the amino acids and proteins within the bacteria are more adapted at certain temperatures.
what is the process of formation of notochord?
Different cell types that differentiate to form the embryoCross section of early embryoPrimitive pitCells that converge go through primitive pit and primitive node go towards the head of the cell (top)Intercalate into the hypoblast - they form a structure called the notochordal plateThe cells in the notochordal plate proliferate and separate to form the notochord
Describe the methods of counting liquid culture growth
Direct counting by microscope- cannot distinguish viable from non-viable cells, not often used.Colony counting (viable counts)- serial dilutions spread on surface of plate =, spread plate, pour plate, Mile-Misma, membrane filtration.Absorbance- measurement of absorbance of liquid culture at 600nm.
PLR test
Direct or consensual PLR is best demonstrated in a dark room with a bright light sourceAfferent supply is the optic nerveEfferent supply is the oculomotor nervePathways - Optic nerve, cranial nerve II through to optic chiasm to oculomotor nerve (III) makes eye blink = directOptic nerve, cranial nerve II through optic chiasm but makes other eye blink = indirect
where is the probe paced
Directly over the tricuspid valve on the right hand signHalf way between elbow and shoulder = right pushed forwardPush and up and underneath tricepsMost images are taken from the right to get to the left
what is elisa used in?
Disease detection Eg canine distemper virus, canine and feline, heartworms, BSE, BVDVDetection of illegal drugs Eg alfentanil, an narcotic analgesic often administered to race horses, or Salbutamol, a bronchodilatorDetection of hormones Eg pregnancy tests
Why is cell membrane function a good target?
Disrupted functional integrity of cell membrane leads to escape of macromolecules of ions from bacterial cell so can no longer functionDisadvantage : high level of similarity between bacterial and animal cell membranesMore toxic for animal cellsHence often last resort antibiotics in human medicine = bactericidalExamples - polymyxin, colistin
superficial digital flexor tendon
Distal end of P1 it splits and inserts on P2Forms a sleeve around DDFT at level of proximal sesamoids (manica flexoria)Flexes proximal and middle phalangeal joints and therefore whole foot - also stabilises fetlock joint
respiration mechanics in avian
During inspiration the sternum moves forward and down and the ribs move cranially and ventrallyLowers pressure in the thoraco abdominal cavity drawing air inExpiration - sternum back and up
Compare the anatomy of birds with low and high flight locomotor capacity?
Eagle =high chicken = lowLarger wing span in high flight locomoterMuch more muscularLarger guts in chickenMore rounded shape of chickenAgile head
Compare the anatomy of birds with low and high flight locomotor capacity
Eagle =high chicken = lowLarger wing span in high flight locomoterMuch more muscularLarger guts in chickenMore rounded shape of chickenAgile head/shape of eagle
outline how osteochondrosis may occur
Early lesions are caused failure of cartilage canal bloody supplyCauses focal areas of ischaemia (insufficient blood supply) associated with that cartilage canal causing: Chondronecrosis/chondrolysisNecrotic canal vesselsthese necrotic regions become incorporated with subchondral bone may form cyst with bone or trauma/weight bearing may cause formation of dissecting lesions - osteochondritis dissecans
Selective serotonin reuptake inhibitors (SSRIs)
Eg fluoxetine, citalopram, paroxetineBlock the re-uptake of serotonin to enhance its functional activityallows more serotonin to be available to be taken up by other nerves.= antidepressant
Tricyclic antidepressants (TCAs)
Eg imipramine, amitriptylineEnhance the functional activity of noradrenaline and serotonin by blocking the reuptake of both neurotransmitters
Monoamine oxidase inhibitors (MAOIs)
Eg selegiline (MAO-B)Enhance the functional activity of norepinephrine, serotonin, dopamine by inhibiting degradation of neurotransmitters by monoamine oxidase
epiglottic cartilage
Elastic cartilageMost flexible and most rostralAttached to root of tongue, body of thyroid cartilage and basihyoid boneDuring deglutition the large blade part partially covers entrance to trachea
blood pressure in different vesselwindkessel effect
Elastin and collagen are present as when the cardiac output occurs those vessels need to recoilHigh level of elastin and collagen in the aorta damp the oscillating cardiac output when the blood leaves / is pushed out the heart - Windkessel effect
regulation of cardiac function?
Electrical activityContractile function controlImportant role of ANSHormonal mechanismsHormonal mechanisms
the beginning embryo
Embryo a disc with three layers: Endoderm Mesoderm Heart - cardiogenic plate of mesodermal tissue at head end of embryonic disc EctodermIt is the first organ to undergo functional differentiation
5 stages of lung development
EmbryonicPseudoglandular Forms glandular tissues Supports function of lungsCanicular Branching, more tubesSaccular Alveoli sacs are beginning to grow and differentiateSurfactant Enables lungs to open and work at birthAlveolar Continues post Nataly
negative emotions vs positive emotions
Emotions are either function or adaptive (helps us survive) significanceNegative emotions eg anxiety promote avoidance or defensive behaviour - flight or fightPositive emotions - pleasure may facilitate ingestive, exploratory, sexual or novelty seeking behaviour
cranial and caudal vena cava
Empty into the right atriumBringing deoxygenated blood from bodyThere is an intervenous tubercule which guides blood into right atrium
structure of lymph nodes
Enclosed in a capsuleAfferent vessels open into subcapsular sinus - bring fluid toInto the trabecular sinusesLymph flows into trabecular sinuses into medulla and medullary sinus - as lymph passes through the node lymphocytes are added and macrophages act as filters to remove microorganisms in an attempt to halt the spread of infection and tumoursEfferent vessels leave at hilus
how are viruses released from the host cell?
Enveloped viruses- budding or exocytosis.Non-enveloped viruses- cell lysis
what is ELISA
Enzyme Linked Immunosorbent Assays (ELISA) techniqueCommonly used antibody-based diagnostic techniques for the detection of specific molecules Eg proteins and carbohydrates in samples
what are examples of diseases caused by viruses?
Epidemic, large scale diseases Foot and mouth diseaseEmerging diseases CoronavirusDisease in individuals or groupsCancer
epidermal lamellae vs dermal lamellae
Epidermal lamellaeSame as epidermis of the skinHorny / keratinisedInsensitiveLine the inside of the hoof wallBasal cells attached to BMBasal cells produce keratinocytesDermal lamellaeSame as dermis of the skinSoftSensitiveContains collagen, fibroblasts, blood vessels and nervesCover P3 and extend up over distal end of P2Basement membrane
Types of haemorrhage what can occur and what are the causes
Epidural hematoma - Occurs when blood accumulates between the skull and outer covering of the brain, typically following a head injury. Can cause a brief loss in consciousness.Subdural hematoma - Collection of blood on the brain surface, typically the result of a the head moving forward quickly and coming to a sudden stop.Subarachnoid haemorrhage - Bleeding between the brain and the meninges covering the brain. Commonly caused by trauma, but may also be triggered by the rupture of a major blood vessel. Symptoms include loss of consciousness and vomiting.Intracerebral haemorrhage - Bleeding inside the brain. It is not usually caused by injury, rather a neurological deficit. Symptoms include vomiting, decreased consciousness, weakness in a part of the body, and higher than normal blood pressure.
what are the components of fungal growth?
EukaryoticGrow at 25 degreesNon photosyntheticCell walls contain chitin and other polysaccharidesHeterophic nutritionUses exoenzymes to digest outside and then absorbs nutrientsSexual or asexual reproductionTolerate high osmolarity and low pHResistant to antibacterial drugs
Describe how to perform an examination of the bovine foot
Examination - you want to arrange the cow in front of you with the cow limb placed into a crush and being held well - make sure cow is happy
streptococcus Equi - cause of strangles
Example of carriage upper respiratory tract24% of recovered animals can shedResides in guttural pouchYou can screen using a nasal pharyngeal swab but it may not pick it up Recommended if carrier for more than 2 months to treat site of infection
mydriasis
Excessive dilation of the pupil
colloid osmotic pressure
Exerted by plasma proteinsPromotes fluid reabsorption into circulatory systemPulling fluid back into the capillary
B lymphocytes
Express membrane bound receptors/antibodiesCentral role in adaptive immunityAble to differentiate into Plasma cells - release antibodies Memory B cells - able to respond if that pathogen seen by host again
Intercostal muscles
External and internal intercostal muscles lie between the ribs Occupy the intercostal spaces Innervated by the corresponding spinal nerves External intercostal lie superficially and fibres run in downwards, forwards and medial direction and insert on superior border of rib below
function of intercostal muscles
External and internal muscles occupy the intercostal spaces between ribsExternal run caudoventrallyInternal run cranioventrallyMuscles used in inspiration and expiration
anatomy of the third eyelid
Extra eyelid that is located mediallyIt has a central T-shaped cartilage inside itGoblet cells cover whole eyelidLots of stromal connective tissueLymphoid follicles present on posterior surfaceNicittans gland at base - tear production roleLacks musculature in the dog, cat has smooth muscle to retract
capsules
Extracellular polymetric material that is secreted around the bacteria and loosely associated with its surfaceHard to visualiseFunction : protect against desiccation (drying), may facilitate adherence to surfaces, may provide a matrix for biofilms of bacteria, some interfere for phagocytosis
reptile eye
Eyelids Some have transparent lower eyelidScleral ossicles - bones surrounding globe providing supportNictating membraneLacrimal/harderian glands
organs with sympathetic supply
Eyes- pupil dilation. - lets light in to see dangerBronchioles- bronchodilation. - dilate airways to access more oxygenHeart- increase heart rate, increase force of contraction. - pump oxygenBlood vessels- vasoconstriction (generally speaking).Adrenal glands- secretion of adrenaline and noradrenaline.GI tract- decreases activity.Bladder- urine retention (bladder wall relaxation and internal sphincter contraction).
adaptations for function in dog
Fast twitch fibres for speed
three basic layers of the eye
Fibrous (outer) layerSclera and corneaVascular (middle) layerUveal tractNeuroectodermal (inner) layerRetina and optic nerve
fick's law of diffusion
Fick's Law of DiffusionLinks together: nature of membrane, surface area, partial pressure gradient, membrane thickness
how is preload controlled
Filling of the heartLow heart rates gives longer amount of times for ventricles to fill with blood = greater force of contractionVenous returnPressure difference between venous system and atriaGreater the difference greater their returnHas four influences : skeletal muscle pump, respiratory pump, sympathetic nervous system activity, blood volume
what are the main structures for adhesion
Fimbriae / pili : most frequent adhesive structure in gram negative bacteria Eg ecoli, salmonella, BordetellaAdhesive macromolecules imbedded in membrane : adhesins Eg streptococcus
What is and where does intramembranous ossification occur?
Flat bonesWidth growth in long bonesMesenchymal cells differentiate into osteoblasts and produce bone directly
axial system adaptations in cat
Flexible lumbar region (back) - increases stride lengthLower gut mass - increased RoM of hipsNuchal ligament reaches to C2 in dogsAxial system leans backwards so the line of force is in a straight lineStill has same function to suspend the head and neck in front of the bodyNo nuchal ligament in catsCan get a really floppy neckCats also have lots of fast muscle fibres in their neck muscles - a reflection of their ambush behaviour
short axis view of the left ventricle
Flipped probe 180 clockwise - so in short axisPlane is switched going across the heartYellow - left ventricle that we can see most of
traumatic reticulitis.
Fluid accumulation in the pericardium decreased cardiac contractility, stroke volume and consequently cardiac output.Renal blood flow and arterial pressure are reduced.
resistance to airflow
Fluid dynamics equationsResistance = length/radius ^4 (halving the radius means 16 x more resistance)Resistance to flow also affected by changes in directionHorses are obligate nasal breathers: Very hard for them to mouth -breatheFlow aided by: ram air into nostrils, straighter head-neck-thorax alignmentHorses have less complex turbinates to reduce resistance
uveal tract anatomy
Focussing on the vascular (middle layer) - uveal tractBlood supply and immune system for the eye
Scatterplots
For each point need to know two pieces of informationShows relationship between two sets of dataOften useful to show a line of 'best fit'
Describe the range of motion of the different joints in the horse
Forelimb - shoulder elbow and carpusMetacarpus up as close to radius and ulna almost 180-degree turnElbow and shoulder are always flexed together - difficult to tell lamenessHindlimb - stifle, tarsus,Hock and stifle joint always work together - reciprocal apparatusFoot flexed and hip will be flexed - there is less flexion in the carpus jointThere is some adduction/abduction of the hip joint which is not present in the shoulder
formation of lung buds
Formation of gutRespiratory diverticulum separates off and forms the lungsContinue to branch and growBetween different animals there are different number of lung lobes - number of original bronchi that branch determines the number of lung budsHighly influenced by surrounding mesenchymal tissue
paranasal sinuses frontal and maxillary sinus
Frontal and maxillary systems common to all - all species have them Frontal sinus Between nasal and cranial cavities Usually drain into ethmoidal meatus: Different in horses Maxillary sinus Caudolateral aspect of upper jaw Around cheek teeth Huge species variability Other = palatine, sphenoid, lacrimal, palatomaxillary Infraorbital - birds
what is the significance of dehorning adult cows to the paranasal sinuses?
Frontal sinus communicates with horn and during removal of horn in adults the sinus is exposed which predisposes it to infectionThe innervation from the horse arises mostly from trigeminal nerveWhen cattle are dehorned there needs to be large amounts of anaesthesiaDon't do where flies are abundant as frontal sinus is opened
Tinbergen's four levels of behaviour explanation
Function (what is the behaviour for?)Evolution (where does the behaviour come from?)Mechanism (how is the behaviour achieved?)Development (how does the behaviour develop in ontogeny- early development?)
inspiration
Function of inspiratory musclesDuring inspiration:Diaphragm contracts - dome flattens and moves caudallyExternal intercostal muscles contract which causes ribs are pulled cranially and outwards= increases the volume of the thoracic cavity
expiration
Function of inspiratory musclesMainly passive - relaxation of intercostal musclesExpiration caused by relaxation of inspiratory musclesRibs recoil back to original position
eukaryotic cells examples
FungiMouldsYeastsParasitesProtozoaHigher multicellular organisms i.e. worms fleas flies etc.)(covered under parasitology teaching NOT all parasites are microorganisms as parasites includes worms, insects etc.)
Functions of the respiratory system
Gas exchange and transport of oxygen and carbon dioxideMetabolic functions Synthesis of surfactant Synthesis and release of histamine Uptake and inactivation of compounds eg prostaglandins Activation of angiotensin by ACEBody temperature regulationBody acid-base regulationVocalisation and displayFacilitates venous return to the heart
how does the outflow differ in the parasympathetic nervous system?
Has craniosacral outflow meaning neurons begin at the cranial nerves and sacral spinal cord
Mast cells
Have IgE receptors on their surface and ' triggered ' when antigens bind surface IgE. Granule contents releasedInvolved in the response to allergy and parastic infections - wormsIn tissues not bloodRounded nuclei, granular cytoplasm, granules released: histamine, heparin, proteasesCan become cancerousMost common cutaneous tumour in dogsDiagnosis by syringe removing some tissue
bacteria virulence factors
Have adhesionsExamples - fimbriae, outer membrane proteins Interact with host cell ligands to increase adhesion of bacteria cellsThis binding may trigger specific invasion mechanisms they survive inside the cell using their specific survival mechanismMay also adhere but not invade just grow and cause damageCan cause local abscess that can spread infection or put pressure on the CNS tissues can cause damageIn this case the site of infection is dictated by where they stick hence you can get abscess in liver, spleen, spinal column junctions - places where blood flow is slowed are more prone to this
Describe how therapeutic regimes are put together for patients with heart disease/failure
Heart disease/failure can have different causes, presenting clinical signs, the disease progression and response to treatment varies. Consequently there is no single therapeutic regime which can be instituted in all patients with heart disease/failure.A number of factors require consideration:Primary causes of the heart disease- valve degradation, cardiomyopathy, idiopathicNon-specific treatment of the primary diseaseTreatment of congestive heart failureIdentify dysrhythmias and treat if indicatedIdentify complicating and co-existing factorsRegular reassessmentWhat does the owner want?
Identify specific species adaptations for locomotion
Highly developed sternum: the keel (carina) is the big ventral body of the strenum which has pectoral muscles inserting, better fliers have big keels, bone marrow aspirate, prone to damage in commercial poultrySkeletonLight, compact and just strong enoughHigher in calcium phosphate than mammalian skeletonsPneumatised bones - a bone that is hollow or contains many air cells Better fliers have more extensive pneumatisationMedullary bone Liable calcium reserve Induced by oestrogens and androgens during reproductive phaseRed muscle High levels of myoglobin, mitochondria and lipid globules Fat is the energy sourceLight, compact and just strong enoughHigher in calcium phosphate than mammalian skeletonslarge pectoral muscles - the rib cage is so rigid to make sure that the thorax does not collapse at contraction of ribsPerching - musculature of legRidges on flexor tendons that fit into ridges on bonesWhen you pull tendons tight they lock so allows perchingHind limb extension releases lock
nasal conchae in birds
Highly vascular epithelial folds in the nasal cavity which increase the surface areaConchae function:Increase the surface areaWarm/humidify airLined by ciliated epithelium=( They filter the air)Goblet cells which produce mucus that are trying to prevent foreign particles entering the oropharynxCaudal conchae - olfactory epithelium
adaptations of the horse
Horse is adapted to the very limits of optimal functionLight as possibleLittle muscular energy as possibleStrong and robust enough to cope with strain
adaptations of the horse
Horse is adapted to the very limits of optimal functionLight as possibleLittle muscular energy as possibleStrong and robust enough to cope with strainCardiovascular system - adaptations are almost mere to making it function at sedentary levelsRespiratory system - coupled with stride rateincrease stride length and increase stride rate OPTIMISES SPEED
Safety issues when carrying out nerve blocks
Horse may experience discomfort or be flighty and cause damage to yourself or the handler: Kicking Biting Barging Throwing headNeedle pricks Medication Zoonotic diseases Insert needle before connecting syringeCompromise of sterility Infection of synovial structuresInability to determine difference in gait post nerve block 'Opinion' diagnosis, differs in peopleLameness may not be limited to a single region or joint
Identify the phases of the cardiac cycle shown by the four sounds heard on this PCG and the species:
Horse- not all will have 4 sounds that can be heard.S1- early ventricular contraction, AV closure.S2- closure of SL valves, backflow of blood.S3- vibration of ventricular wall duringpassive filling of ventricle.S4- ventricular filling due to atrial contraction.
list four most common sites of OCD in the dog and horse
HorsesTibiotarsal joint - distal intermediate ridge of tibia or lateral trochlear ridge of talusFemoropatellar joint - lateral trochlear ridge of femur and patellaFetlock jointLess common - shoulder elbow hipDogShoulder - caudal aspect of humeral headStifle - lateral femoral condyleElbow - coronoid process of the ulna and medial condyle of humerus.
summary of SIRS
Host response to pathogens is a double-edged sword and can lead to severe complications such as sepsis and MODSSepsis SIRS & MODS is generally caused either by localized infections turning systemic or breakdown of protective barriers allowing bacterial entry.Sepsis, SIRS & MODS lead to high morbidity and mortality with currently limited therapeutic interventionsTherapeutic intervention is very difficult since a careful balance has to be achieved to prevent detrimental effects without suppressing beneficial effects
intracellular survival
How to get inside the cell?Phagocytic cellsForced phagocytosis - manipulate cellsHow to move inside the cell?Inside the cell is very viscousManipulation of host cytoskeleton - actin and - microtubulesHow to obtain nutrients inside the cell?Manipulation of host metabolismSurvival - modify vesicle trafficking (prevent fusion of phagosome with lysosome) or escaping the phagosomeListeria haemolysis is rapidly degraded by proteasomes
thyroid cartilage
Hyaline cartilageForms most of the floor the larynxRostral part forms the Adam's appleArticulates with thyrohyoid bone and the cricoid cartilage
arytenoid cartilage
Hyaline cartilagePaired and articulates with the rostral part of the cricoid cartilageVocal process present where the vocal folds attach
cricoid cartilage
Hyaline cartilageSignet ring shaped wider on the dorsal surface than ventralArticulates with thyroid cartilage
parts of the larynx
Hyaline cartilagesMain elements of larynx Thyroid - U shaped Cricoid - signet ring shape Paired arytenoids - sort of triangularElastic cartilage Epiglottis - leaf shaped
dynamic equilibrium of interstitial fluid
Hydrostatic pressure = P (arterial end) > P (venous end)Pressure falls as the fluid travels
Clinical signs due to changes in pulmonary vasculature
Hydrostatic pulmonary oedema - worsens hypoxia and have soft 'wet' cough and shallow fast breathingPredisposed to secondary pneumonia as proteinaceous fluid ideal for bacterial growth
List of ruminant diseases with neurological presentation?
HypomagnesemiaBSE (scrapie, rabies, Aujeskey)MeningitisBrain/spinal abscessListeriosis - unilateral facial paralysisPEMLead poisoningNervous ketosis
Interpret the results of nerve blocks and make decisions on further diagnostic tests
If none, where the lameness is now present the further diagnostic tests of MRI radiography and ultrasonography, can go ahead to ensure that the damage can be discovered but the region has now been determined for these tests
how does contractility increase stroke volume and preload
If we increase the contractility - forces on ventricle wall then we get ventricles that will contract to a greater extent increasing the amount of blood ejected out the heart (stroke volume)Increases the contractile force enabling the heart to be able to handle a greater pre load, empty more completely, allows this against an increased after load, and enables an increased stroke volume
5 types of immunoglobulins
IgA, IgD, IgE, IgG, IgM5 types of immunoglobulinsMany different variable regions so the chance of matching to pathogens is greaterAs B cell further differentiates - crossing over of genetics and combinationDifferent appearances and binding influences different roles
key role of central nervous system
IgE antibodies have been formed since B-cell first came into contact with antigenIgE bind to mast cells/basophils in mucous membranesIf allergen encountered again mast cells/basophils degranulate and release a large amount of histamine and other inflammatory mediatorsInflammatory mediators lead to smooth muscle contraction around bronchioles directly and via CNSBronchoconstriction
Generalised progressive retinal atrophy (gPRA)
Important cause of inherited blindness in pedigree dogs e.g. Toy and Miniature poodles, Labrador retrievers, English Cocker spanielBilateral symmetrical degeneration of neurosensory retinaGradual loss of visionSecondary cataract commonNo treatmentNormally starts as night blindness as effects rods first
bicarbonate buffer system
Important in blood, pKa is about 6.1 meaning its chemical buffering capacity at 7.4 is poor but as it is open at both ends it is a highly effective systemCarbonic anhydrase is an important enzymeprimary role to prevent changes in pH caused by organic and fixed acids in the ECF :
General Examination historyhow conclusions
In a hands off manner and obtaining information from the ownerHistoryTaking a thorough history is essential. Especially in those conditions which may be transient such as seizures, since the abnormalities for which the animal is presented may not be manifested during your examination.How?General observation of the animal on approach to the examination room and interaction with owner and its surrounds allow you to asses for mental status, posture, gait, muscle condition and response to the surroundingsConclusionsShould have an idea of the probable location and extent of nervous system dysfunction that you can test with the rest of your examination
why is the myelin sheath is so important to define the velocity of the nerve impulse conduction.
In a myelinated axon the axolemma (part of cell membrane which covers the axon) is surrounded by a myelin sheath that is interrupted at regularly spaced intervals by myelin - free gaps called nodes of RanvierAt the junctions the nerve fibre plasma membrane - axolemma is directly exposed to extracellular fluid Whereas the sheathed portion of nerve fibre is insulated (nodes are insulated)Depolarization occurs at the nodes of RanvierMyelin sheath allows electrical impulses to transmit quickly and efficiently - travelling wave of depolarisationSaltatory conduction = action potentials occur at the nodes of Ranvier and the localised circuits arise between adjacent nodes of Ranvier and the action potentials in effect jump from node to node
B - cells
In the bone marrow, self antigen is presented on stromal cells.If B-cells responds to this self antigen through their B-cell receptor there are two different routes:= interaction leads to cell death by apoptosis= Receptor editing (re-arrange BCR genes to avoid recognition of "self" antigens) - unique to B-cells!Educated naïve B-cell express both, IgD and IgM on their cell membrane
cardiomyopathy
In the dog - usually DILATEDDisease of the heart muscleMuscle function is poorHeart does not pump effectively
suspensory apparatus
In the forelimb we have serratus ventralis forms a suspensory sling - supports scapular and humerus against side of horses bodyHowever would result on shoulder flexion if not counter balancedShoulder maintained in extension by supraspinatus muscle and co-operative antagonism of biceps
where is the thermoregulatory centre located?
In the hypothalamus and it contains receptors sensitive to the temperature of the blood
things that can affect exercise performance
Incline ~12% increase in workload per 1% increase in gradientGround conditions ~19% increase in workload on muddy (going = soft) ground Track being turf, sand or fibre?Thermal environment ~10% increase hot vs cool, hot/humid vs hot Altitude (barometric pressure)Rider to horse weight 600 kg horse + 10 kg child +1.7% 350 kg horse + 70 kg adult +20%
how can bacterial growth be measured in liquids
Increase in optical density over time- a measure of absorbance of light- normally around 600nm wavelength, the more bacteria, the greater the absorbance of lightGeneration (time for one full round of division)Growth rate- how much doubling per hour
variable in CSF = total protein cisternal and lumbar normal finding change due to bacterial infection?
Increase in the proportions indicates an immune mediated response
Stopping Anaesthesia process
Increase the dose of the agonist the dose response curve will shift back to original state You can use an indirect agonist with anticholinesterase Increase concentration of Ach as anticholinesterase will stop the metabolism of Ach As its inhibiting the enzyme Get a higher concentration of Ach which will replace/shift antagonist from the receptor
Describe the mechanisms of venodilator drugs
Increase venous capacity, decrease preload, reduce fluid build up. Drops pressure in veins.
factors governing diffusion at the tissues
Increased heat and pH shift curve to rightBohr shift Increased carbon dioxide, decreased pH=unloadingEach occur in metabolically active tissues
Noradrenalinea and b agonist
Increasing the heart rate it is not selective for alpha or beta so we don't know which adrenoreceptor type is in the heartwhat causes increase in arterial blood pressure?as cardiac output has increased in a non-pithed rat elevated and increased blood pressure sending signal to central nervous system to reduce the heart rate and normalise system
septic focus
Infection present in a limited area of the body such as the tonsils or sinuses - in this case a pus filled swelling in the brain
uveitis
Inflammation of the uveal tractChorioretinitisPain - blepharospasmRed eye - conjunctival and episcleral hyperaemiaMiosis - swollen dull-irisInflammation - in anterior chamberLow intraocular pressureCorneal oedema - vascularisationSecondary consequences: synechiae, secondary glaucoma, cataract, retinal detachment, retinal degeneration, optic nerve atrophyTriggers of uveitis - the eye can be common target for inflammation
how does inflammation cause bronchoconstriction
Inflammatory cells infiltrate the lungs and release mediators that augment the inflammatory response in the epithelium, creating a cycle of chronic inflammation. This process causes bronchoconstriction and epithelial damage, and it can result in remodelling of the airway.
Schiff Sherrinton syndrome
Information passes from the lumbar intumescence to cervical intumescenceForelimb have rigid extension (increased tone)Inhibitory interneurones (border cells) between the forelimb and hindlimb have been sliced
Where would you pass a naso-gastric tube or endoscope?What forms the dorsal and nasal conchae?Within what structure does the frontal sinus extend? What is this sinus known as?
Infraorbital canal through middle meatusCoiled fragile laminaeThey originate from the ethmoid bone and attach to maxilla - dorsalOriginate from maxilla and extend further into nasal cavity - ventralExtends into the middle meatus and drains through the nasofrontal duct and into the frontal recessFrom notes : usually drains into ethmoidal meatus
How does Listeria invade move in cells and move between cells
Ingestion of contaminated feed an my result in septicaemia, encephalitis or abortionMoves in cells?Spread occurs via lymph and blood to various tissuesOrganism can invade through breaks in the oral or nasal mucosaMigration in cranial nerves is thought to be the main route of infection in neural listeriosisMove between cells?Can survive and replicate intracellular and to transfer to cell to cell without exposure to humoral defence mechanism
angiography - selectiveLV
Insert catheter into femoral artery. No leaking contrast
Three mechanisms of microbial pathogens causing damage to the nervous system?
Invade and replicate in the tissuesDirect invasion of peripheral nerves.From adjacent structures such as from the meninges.From the blood Haematogenous.induce a damaging immune responseInflammation of CNS Damage cause by local inflammation to the CNS Auto-immune response. Human example Guillain-Barré syndrome due to CampylobacterDamage the nerve by neurotoxinblock signallingdamage specific cells
ion channel / ligand gated
Ion channel = neuronsLigand gated = peptidesExamples - angiotensin 2, vasopressinA protein sitting in a lipid bilayer of a cell - something binds to a extracellular area on the channel which causes a conformational change in the protein opening it allowing specific ions through
Outline how a disease can spread within a population
It can live up to 14 days on the foot and longer in foot trimmingsIt can spread within the population over pasture as the sheep are together and the anaerobic bacteria is able to survive for a long amount of time
interatrial septa = SP and SS
It grows towards the AV cushionsDevelopment of prongs O1 and O2Horseshoe shapedGrowth of tissue up from AV tissues and the two prongs will eventually overlap - they are not stuck together so allows blood to flow between the two atriaMaintain right to left flow - second septum develops = septum secundum which forms a second foramen
hypocretin
It is a facilitatory neurotransmitter involved in appetite control and neuromodulation of sleep
Angiotensin IIRAAS system
It is a vasoactive peptideCells in the kidney store renin that gets released upon a sense of drop in blood pressureCirculates around the body to make AT1 which is fairly inactive but as it goes through the lung it is converted into AT2 which is very vasoactive - causes direct vasoconstriction and can cause noradrenaline release
The sinoatrial (SA) node where is it?what does it do?
It is located in right atrium controls the rhythm of the whole heartReaches threshold potential firstChanges to permeability to different ions make action potentials
Describe the general role of the ANS
It is part of peripheral nervous systemUnconscious and autonomicIt reacts to the situation to try keep the body alivetwo components parasympathetic and sympathetic : keep body ticking over and ready for anything
explain how the clinical signs of OCD relate to underlying pathology
Joint effusion - abnormal amount of fluid on the jointLameness (cartilage aneural) more likely if:Subchondral bone involvement SynovitisOnset clinical signs often associated with exercise/trauma May convert silent OC to OCD
structure of tear film
LAME - lipids, aqueous, mucin, epithelial7-8um thickLipid - limits evaporation - thick tear filmAqueous - most of volumeMucin - aids spread and adherence of tear filmEpithelium
Describe the phases of growth of bacteria in liquid cultures
Lag phase- bacteria start to metabolise and growExponential phase- division of bacteria, doubling each timeStationary phase- bacteria reach a limit on resources (limiting factor)Decline/death phase- bacteria are exhausted of a component needed for growth, new bacteria cannot grow.Consider the bodily environment- may take longer to get to the stationary phase, e.g. intestinal infection will have a continuous food supply.
Describe and apply the principles of mobility scoring in cattle to identify lameness
Lameness of the cow is graded with 4 categories - locomotion score focussing on cows needed treatment0. Good mobility and no sign of pain and flat back and long fluid stridesEarly signs of lameness - mobility imperfect steps are unevenImpaired mobility - uneven weight bearing on the leg that is immediately identifiable - normally an arch to the backSeverely impaired mobility - can't keep up with the healthy herd
general structure of neurones?
Large cells which consist of :Cell bodyProcesses (poles) which include one single axon and one or more dendrites (inputs to cells)Processes, poles, neuritesAxonMay extend up to a metreResponse for transmission of nerve impulses away from the cell bodyRemain single until axon terminals are reachedA few collateral branches at right angles to the main axon may occur
avian eye
Large compared to headLarger and sharper images compared to mammalsNictitating membrane - 3rd eyelid = rapid sweeps which clean corneaLacrimal and Harderian glands = keep the surface of eye lubricated
Macroglia
Large glial cells such as oligodendrocytes, Schwann cells, and astrocytesOligodendrocytesInsulators in CNSSchwann cellsInsulators in PNSEpendymal cellsMake CSF and form blood-CSF barrier
natural killer (NK) cells
Large granular cytotoxic lymphocyteRole in destruction of virus infected cells
cervical vertebrae characteristics
Large plane joints orientated parallel to the ground between the joint processes of cervical vertebraeThey are synovial jointsAllow side to side neck and allows neck up and down
lumbar vertebrae characteristics
Large transverse processLarge dorsal spinous processJoint processes are vertical
cardiomyocytes
Large, cylindrical cellsStriated (myofibrils) Work like skeletal muscleShort branched fibres Allows interconnectivity Contracts at exactly the same timeLots of mitochondriahistologyAll the cells in the ventricle contract almost at exactly the same timeCardiomyocytes are excitable cells, functional syncytium, the structure facilitates fast action potential passageT tubules allow quick reuptake of calcium - allows cells within the ventricle and atria to relax/contract quickly
Describe the location and normal dimensions of the feline heart on radiographs
Lateral Radiograph- width of heart is two IC spaces.Normal DV- width is 0.66 width of thorax at 5th rib.
Identify the veins, arteries and nerves in this photo.
Lateral digital veinLateral digital arteryLateral digital nerve (median nerve)
life cycle of cattle lungwormdictyocaulus viviparus
Latter half of first grazing seasonAffects cattle on permanent pasturesThey have to malt twice to become infective from L1 TO L3Cattle develop immunity after exposureHypobiosis (dormancy) of late larval stage has been demonstrated in adult cattleL3 larvae may overwinter on pasture in enough numbers to cause disease
How does the atrial septae form?
Left and right atria separated by atrial septum 1It grows towards the AV cushions development of prongs O1 and O2
Describe the differences in the great vessels of the heart in the cow/sheep/goat compared to the dog
Left subclavian artery branches off the brachiocephalic trunk rather than the aorta.The left and right common carotid arteries branch later off the brachiocephalic trunk resulting in a section of the brachiocephalic trunk called the bicarotid trunk.There is a left azygous vein which branches off the caudal vena cava.
circling - vestibular vs forebrain
Lesions which causes the animal to spontaneously circle may have either a vestibular or forebrain localisation and can be on either the left or the right side of the brain. Animals which present circling will most likely be circling towards (the side of) the lesion. the dog has a head tilt indicative of a vestibular lesion. The Yorkshire Terrier by comparison has a head turn which would be consistent with a forebrain lesion.
Cranial nerve VIII - vestibulocochlear
Less effected in equine species than othersCan check hearing with a clapOn the right - profound head tilt due to reduced sensation from the cochlear apparatus
primitive cardiac tube
Like a pulsatile toilet roll in this stageTwo lateral extensions of the cardiac disc hollowed out Forms pair of endothelial tubes which soon fuse to form the primitive cardiac tube when the embryo folds laterally
what is surfactant
Like washing up liquidIt enables alveolar cells to touch one other without sticking90% phospholipid, 10% proteinMade by type II pneumocytes in lungsIf there is no surfactant then respiratory distress syndrome occursFluid filled lungs have very low compliance (cannot open) as water has high surface tension, Air - filled lungs are very compliant due to surfactant reducing surface tension
limitations of cardiac ultrasound
Limited area for imaging heart through the cardiac notch due to air in the lungsRibs - bones limiting the imaging window so need a probe small enough Os Cordis in cattleDistance problem in large animals as depth will not be large enoughAnatomy of the forelimb may limit the imaging angle
what changes are seen in the brain at altitude
Low PaO2 and cerebral oedemaCerebral oedema is partly due to vasodilation in the brain due to it being in a closed box you get an increase in pressure and leads to leakage of fluid into cerebral tissue Ataxia, wobbling, dysphoria, aggression, coma and death, irritability and headaches Cattle look like BSE
how is ventilation regulated
Lungs provide oxygen and remove carbon dioxideRespiratory centre is in the brain stem in the medullaGenerates action potentials Modulated feedback from Chemoreceptors - detection of arterial gas levels Mechanoreceptors - stretch receptors within the lung
Describe the positioning of dogs and cats for ventrodorsal thoracic radiographs
Lungs, chronic cough cases looking at specific lung detail- puts lungsvery close to the plate- cardiac silhouette is distorted though, notappropriate for animals in respiratory destress.Place animal in dorsal recumbency.
What are lymph vessels and what is the flow like?
Lymph vessels are similar in structure to veins but are more delicateflow is unidirectional - away from tissues and returning at point of cranial vena cavaFlow is mainly passive and is maintained by valves and contraction of surrounding skeletal muscles and arteriesLYMPHOEDEMA Localised fluid retention and therefore tissue swelling
differentiating cells of the immune system
Lymphocytes differentiate into plasma cells They secrete antibodies in large amountsT and B cells can be effector cells or memory cellsCirculate around body waiting to reactivate if same antigen is encountered againSecondary immune responseMonocyte - normally irregular nucleus / bean shaped
acetylcholine receptor and affecting transmission?
M1 - autonomic gangliaM2 - heartM3 - smooth muscle & secretory glandsM4&5Detected by molecular cloningACh (no clinical use- is metabolised so quickly)ACh releaseACh metabolismEach step can be targeted pharmacologically to modulate transmission. Will have effect on both muscarinic and nicotinic synapses.
two classes of MHC molecules?
MHC CLASS I = every nucleated cell presents endogenous 'self' peptides - in a healthy cell it is self but if infected by virus then those cells will present viral proteins - signal to be destroyedMHC CLASS II = on antigen presenting cells (B cells, dendritic cells, macrophages) present exogenous (non-self) peptidesSimilar function Involving delivery of short peptides to the cell surface for recognition by CD8+ and CD4+ T cells respectively
Describe how T and B lymphocytes that react with 'self' proteins are removed during their development
MHC molecule display peptides which are sampled by B and T cells to identify if non-self or selfHealthy cells MHC groove is filled by a peptide generated by the cell Self peptideInfected host cell MHC groove is filled by a peptide derived from pathogens proteins Non self peptide
Understand that different imaging modalities are useful for imaging different tissues and different parts of the distal limb
MRI you are able to see the fluid contained (percentage of water content) - eg bone marrow
Identify a number of methods suitable for disseminating knowledge to farmers
MagazinesWord of mouthLettersEmails
diaphragm anatomy and innervation
Major muscle of inspirationMade up of striated musculatureMotor and sensory innervation is from the phrenic nerve Originates from C5-C7 Insertion at inner aspect of thorax, ribs, sternumvia two crura to lumbar vertebrae
Stride rate
Maximised by reducing the distal limb massUse of tendinous leversDuring protraction flexion of the limb reduces the radial distance of centre of massinertia = mass x radial distance(squared)Heavier it is at the bottom the more difficult to increase stride rateRemoval of bones - digits and metacarpals
What drives perfusion
Mean arterial blood pressure- we can measure it by feeling the pulse (is tricky), invasive measurement and non-invasive measurement
What structures (veins, arteries and nerves) pass across the surface of the guttural pouch
Medial compartment:internal carotid, cranial nerves X, IX, IXLateral compartment:stylohyoid bone, external carotid
Outline the process of thrombopoiesis
Megakaryocytes which form platelets - cycle that is kept in balance by negative feedback
Label and describe the key features of platelets
Membrane-bound fragments of cytoplasm from megakaryocytesSurface glycoproteins (GPs)Phosphatidyl serine (PS)- sticky for blood factorsRich in microfilaments and microtubules - allowscontractionOrganelles- alpha granules (a), dense granules/bodies (d), g and l granules
Cranial nerve II - optic nerve test
Menace responseBlink Brought about by motor part of facial nerveWithdraw response Central processing and cerebellar - involves fore brainLearned response not a reflex Absent for first 14 days of lifePupillary light reflexDirect and consensual responses Oculomotor nerve (CN III)Anisocoria - any animal with different sized pupils
describe the general architecture of the vascular system of the spinal cord and brain
MeningesSeries of layers of membrane surrounding the central nervous system both the brain and the spinal cordLayers of meninges three layers- dura mater, arachnoid mater, pia materfunction: Protection, containment of CSF, maintenance of BBB (blood brain barrier), support
examples of angiogenesis
Metabolically active tissues need to be close to a capillary for gaseous exchangesLimited angiogenesis in adults mainly just female reproductionPathology - wound healing, skin/heart disease, tumour development
Oxygen cannot bind to the haemoglobin or cannot get off teh haemoglobin causing hypoxia
Methemoglobinemia Elevated amount of met haemoglobin in the blood Can be caused by paracetamol toxicity Met haemoglobin carries oxygen through the blood but doesn't release it into the cells Starts to replace normal haemoglobin so oxygen isn't released or reach tissues Carboxyhaemoglobin is normal Hb with Co2 binded to it - this has a lot more affinity for Hb than oxygen. Which means that carbon monoxide is bound in place of oxygen
Dirofilaria immitis life cycle
Microfilariae in the dog blood is ingested by mosquitoBecomes L3 infectiousMosquito is an essential intermediate hostInfectious L3 transferred to the dog when they bite which will move towardspulmonary arteries where they meet sexual maturityL4/L5/adult - right heart and pulmonary vessels
What parts of the brain stem control alertness, awareness and consciousness?
Mid brain (mesencephalon)Associated with vision, hearing, motor control, sleep and wake cycles, alertness
variable in CSF = cytologynormal finding change due to bacterial infection?
Monocytes, lymphocytes, rarely neutrophilsIncreased neutrophils is a sing of bacterial or early viral CNS infection
Monocytes/macrophage
Mononuclear phagocytes = engulfs and destroys bacterial pathogens through digestion with lysosomal enzymesThey circulate in blood and differentiate to macrophage after migration into tissuesMacrophages are able to act as antigen presenting cells with a central role in both, innate and adaptive immunity
parasympathetic nervous system
More targetedRest and digestCranial & sacralGanglia in/close to effector organLong pre-ganglionic neuron, short post-ganglionic neuronoutflow from parasympathetic the brain (cranial nerves) or sacral region (pelvic nerves)Cranial nerves - provide majority of PS supply to organsPelvic nerves - provide PS supply to pelvic organs
Identify the carbon sources for bacteria
Most bacteria require carbon and nitrogen in usable forms in large amounts.Carbon is the main constituent of organic compounds (and therefore structures) of bacteria.Microbes can be divided by their preferred carbon and energy sources- chemical compounds or light.
iris structure
Most of the iris is made up of the stroma : lots of fibrous connective tissue, collagen bundles, pigmented and non pigmented cells, blood vessels and iris sphincter muscleAnterior surface - contains iris dilator muscle (opens the pupil)Posterior surface - bilayered iris epithelium
Explain why association neurons are involved in the reflex arcs.
Most reflex arcs the sensory neuron connects to the motor neurons through association neurons (interneurons)These allow transfer of information between neuronsAs sensory neuron needs to transfer information to the motor neuron to cause a effector response the interneurons are involved
eye anatomy amphibian
Move lens towards or away from the cornea = accommodationIris is striated muscleVision involves pattern recognition as they don't have good visual acuityRetina processes 90% of info
mitral valve
Move sligthly higher up the body wall to get mitral valveFish mouth view - mitral valveStill imaging from right
Left parasternal long axis view of the left ventricular outflow (aorta)
Moved angled more cranially towards right side structuresMain focus is the aortaMuch better alignment of the probe and direction of blood flow this way
long axis view of the right ventricle
Moving even more craniallyGets right sided outflow tractTcv - tricuspid valvePv - pulmonary valvePa - pulmonary artery
what is MLST and how does it work
Multilocus Sequence TypingA procedure which characterises individuals of a microbial species using DNA sequences of multiple housekeeping genes.For each gene, the different sequences of the individual isolates are aligned with others and they are matched and compared at each loci to determine the sequence type (ST).They are genes needed for bacteria to grow and so are commonly found and are not too heavily modified
Name the three different structures of neurons found in the body and give example of anatomical locations
Multipolar - Central nervous systemBipolar - Restricted mainly to special sensory pathways(pseudo)Unipolar - Peripheral nervous system
msk diseases in cat
MuscleTraumatic injuriesCat bites - cellulites/abscess/osteomyelitisJointsTrauma - disruptionDevelopmental - rareBonesTrauma - RTAsCaudal equina syndromeFractured pelvisFractured limb bonesNutritional secondary hyperparathyroidism if fed an all meat rationDevelopmentalLuxating patellaRare compared to dog
diaphragm location
Muscle is attached to the xiphoid process (sternal part) to the inside of the lower costal cartilages and ribs by digitations (costal part) and to vertebral column (vertebral part)
adaptations for function in cat
Muscles for anaerobically processes and explosive energy and muscles to ears to locate soundsRetractable claws to secure preyGreater range movement in spine and shoulder than dogWeight bearing during walkingAntebrachium range of pronation 45-55 degrees
how can DNA be used to differentiate between closely related bacteria?
Mutations can occur within a small population and genes may also be lost or gained. The pathogen can be sequenced to compare DNA structures since DNA is not constant.
neutrophil development in bone marrow
MyeloblastPromyelocyteMyelocyteMetamyelocyteBand neutrophilSegmented neutrophilleft shift When strong inflammatory demand more neutrophils in circulationBegin to see immature neutrophils or 'band forms' within the blood
structure of respiratory tract
Nares & nasal cavityParanasal sinusesPharynxLarynxTracheaBronchiBronchiolesAlveoli
sense of smell in amphibians
Nasal sac, vomeronasal oran, nasolabial grooves
sense of smell in fish
Nasal sacsWater carries chemicals in choana (internal naris)
autonomic reflexes
Neural regulation of the ANS occurs by reflexes - autonomic reflexesThey work through feedback mechanisms which involve the afferent nervous system. Their function is to maintain homeostasis
Discuss the role of prions in the development of TSEswhat are TSEs?
Neurological disordersNeuronal lossInvariably fatalVery long incubation periodsIt is caused by a misfolded prion proteinProtein only hypothesisPrion protein - unknown function, host encoded high expression levels in CNSMisfolded is PrPSc - beta sheets = it is spontaneous but can be inherited
where are receptors for hypocretin found?
Neurons in locus ceruleus and dorsal raphe nucleuslocus ceruleus neurons release norepinephrinedorsal raphe release seratonin= both of which are inhibitory at their termnation in the pontine reticular formation nucleus
the nucleiod
No nucleus but the genome is tightly organised and packedCompacting is achieved by super coiling the DNA Involves strand braking and passing the loop through the break and reforming the break using the DNA gyrase enzyme which is unique to bacteria Formation of protein complexes with DNA binding proteins (histones like proteins) further packages the DNA
thoracic vertebrae characteristics
No transverse processes as there are regions for articular surfaces of the ribsDorsal spinous process relatively long; vary on regionLow mobility so joints are small
snake hearing
No tympanic membrane but not deaf The quadrate bone receives vibrationsStapes attached to quadrateCapable of detecting low frequency sound= quadrate= stapes/columella= oval window
Nociception:
Nociception:The neural process of encoding noxious stimuli. Nociceptive pain (pain from activation of nociceptors)Noxious stimulus:A stimulus that is damaging or threatens damage to normal tissues
classifications of learning
Non-associative learning :HabituationSensitizationAssociative learning:Classical conditioningOperant (instrumental) conditioning = process of learning to automatically have a particular response to the presence of a stimulus
B receptor activation
Norepinephrine acts at beta get higher, shorter action potentials-stronger, quicker contractionsIncreases Ca2+ entryK+ channels open soonerRate rises - +ve chronotropic effectForce of contraction increases - +ve inotropic effect
normal fundus variations
Normal fundus variationsDepends on overall pigment in individualCoat colour, iris colour and fundus colour are linkedTypical colour combinations dog, herbivore: strong coat colour, brown iris, overall yellow/green/blue fundus with obvious tapetum Cat: strong coat colour, dark yellow iris, overall yellow fundus with obvious tapetumReduced pigment in coat typically associated with blue iris and reddish/brown or red/white appearance of fundusSclera and neurosensory retina do not changeSclera is white: neurosensory retina is transparentChoroid and tapetum and RPE most likely to change
Describe the appearance of normal thoracic vasculature on radiographs
Normal pulmonary vessels are clearly visible in central and middle zones. Vessels taper towards the periphery.
muscles of the nostrils
Nostril dilation Levator nasolabialis Caninus Transversus nasi Important mainly in the horseAll innervated by the facial nerve, supplied blood by facial artery
larynx in avian
Not covered by a epiglottis/soft palateSlit like openingMuscles around it control the passage of air4 cartilages present in the larynxNo thyroid and epiglottis
canine cognitive dysfunction
Not normal part of ageing main symptoms can be summarized by acronym DISHDisorientation, interaction changes, sleep changes and house soiling
process of neuralation of chick embryo
Notochord Sends these signals makes ectoderm clues go to neuroectoderm cells and sends signals thickening forming the neural plateFolding and new hinge at neural crest which elevatesAfter elevation there is convergence of neural foldsFusion of neural foldsCells trapped above tube = neural crest cellsThe neural crest cells migrate to regions in body to form many structures
what are the four long vertebral ligaments?
Nuchal lig : occipital bone - 3/4 thoracic vertebraSupraspinous lig - thoracic vertebra 3 - sacrumVentral longitudinal lig - 8 thoracic vertebra - sacrumDorsal longitudinal lig - vertebral canal, neck - sacrum
What is the mature virus particle (virion) is composed of?
Nucleic acid (genome)Surrounded by a protein coat (capsid)The surfaces may have embedded proteins which help the virus to enter cellsSome have lipid envelopes
Quadriceps femoris - Rectus femoris
O: IliumI: Tibial tuberosityA: Extend stifle and flex hipN: Femoral nerve
Sartorius
O: Ilium and thoracolumbar fascia. Iliac spine and iliumI: Patella and cranial border tibiaA: Flex hip and flex or extend stifleN: Femoral nerve
Superficial digital flexor
O: Lateral supracondylar tuberosity of femurI: Tuber calcanei and MP 2, 3, 4 and 5A: Flex stifle, extend stifle, flex first 2 digital jointsN: Tibial nerve
Gastrocnemius
O: Medial and lateral supracondylar tuberosities of femurI: Tuber calcaneiA: Flex stifle and extend tarsusN: Tibial nerve
Internal obturator
O: Pelvic symphsis and dorsal ischium and pubisI: Trochanteric fossa of femurA: Rotate laterally at hipN: Sciatic nerve
Adductor
O: Pelvic symphsis, ischiatic arch, ventral pubis and ischiumI: Lateral caudal femurA: Adduct limb and extend hipN: Obturator nerve
Quadriceps femoris - Vastus lateralis, vastus intermedius and vastus medialis
O: Proximal femurI: Tibial tuberosityA: Extend stifle and flex hipN: Femoral nerve
Deep digital flexor
O: Proximal tibia, proximal fibulaI: DP 2, 3, 4 and 5A: Extend tarsus and flex digitsN: Tibial nerve
Quadratus femoris
O: Ventral caudal ischiumI: Intertrochanteric crestA: Extend hip and rotate laterally at hipN: Sciatic nerve
neurological exam cattle
Observation = Posture, behaviour, muscle tone/atrophy, symmetryGait on halter if halter trained= Proprioception, incoordination, ataxiaStraight line away from you and circle left and rightPanniculus - skin sensitivityExamination of the head - facial symmetry, nystagmus, strabismus, palpebral reflex, cornea reflex, menace responsePupillary light reflexInspect oral cavity (use palatum reflex) - tongue paresisSwallow reflex
poultry swabs
Observe clinical signs in commercial flocks such as head shaking, swellings around the head, discharge / dried nasal crust or conjunctivitis, a loss in production may also mean swabs of the upper respiratory tract are taken as part of a flock investigationGenerally tracheal swabs are taken small enough to fit through the glottisCloacal swabs will also be taken
Before the neurological exam
Observe from a distanceChanges in mentationAbnormalities of cerebral functionAbnormal states of wakefulness
Clinical exam of cattle
Observe from a distance - BCS, RR, gaitHead to tail body systemsWhat is normal/abnormalSigns of ill health - elevated temp/respiratory rate, discharge etcCow sheep : rumen turnover, udder, MM assessment
Describe the cell-based coagulation model of secondary haemostasis
Occurs at the location of damage. Intrinsic and extrinsic systems generate FXa in parallel on different cell surfaces.Initiation:Injury exposes TF-bearing cell to flowing blood- small amount of FIXa and thrombin generated.Amplification:Thrombin activates platelets (exposing PS)vWF released (tethers platelets to site of injury by binding to GPIb/FIX receptor on one hand and subendothelial collagen onthe other)Leads to generation of FXI, FVIII, FVPropagation:Factors assemble on the activated platelet to form intrinsic tenase (FIXa, FVIIIa and Ca2+)Results in FXa generation on the platelet surfaceProthrombinase complex (FXa, FVa, Ca2+) forms and results in a burst of thrombin generation directly on the platelet (stabilisation)
anthrax toxin
Oedema Toxin Protective antigen Binding Oedema factor This leads to calmodulin-dependent adenylate cyclase Leading to more cyclic AMP Leads to oedema formationLethal Toxin Protective antigen Binding Lethal factor Zink metalloprotease Stimulates cytokine release Overactive immune responseLeads to oedema and necrosisCattle and sheep you get septicaemiaPig and horses you get haemorrhagic enteritisBoth lead to death
name the openings in the diaphragm for?oesophagus
Oesophageal Hiatus - contains the oesophagus, dorsal and ventral vagal trunks
neonates born at altitude?
Often born with pulmonary hypertensionSmall number have signs as described of altitude diseaseFetal circulation may also not develop into adult circulation because of abnormal pressure dynamics in heart Persistent ductus arteriosus (aorta to PA) Persistent foramen ovale (between atria)
sense of smell in birds
Olfactory bulb size related to lifestyle - smallest in seed eaters and largest in aquatic animals that rely on scent
what happens when Light stimulates retinal neurons?
Optic nerve axons activate neurones in the suprachiasmatic nucleus in the rostral ventral hypothalamusAxons from suprachiasmatic neurons terminate in a ventrolateral nucleus in hypothalamusThese latter hypothalamic neurons project diffusely in the prosencephalon and brainstem and release the neuropeptide = hypocretin=It is a facilitatory neurotransmitter involved in appetite control and neuromodulation of sleep
Describe the anatomy and the biomechanical function of the equine foot
P1 2 and 3Navicular bone and bursa - filled with synovial fluid and protectsDigital cushionSoleFrogSulcus of frogThe digital flexor tendon sheath - protects the DDFT and SDFT from damage as these are so importantVascular foramina of the distal phalanx - allow blood supply to pedal bone
pros and cons of emotional state drugs
PROSQuick effectsSome patients very effectiveUseful to support behavioural techniquesCONSUnwanted effectsSpecies differences impact on toxicityParadox effects
keratin tubules
Papillae form themThey are squames bound togetherHollow due to loss of central papilla as tube elongatesTubules secured to each other by inter-tubular horn - bottom of the tubes those keratinising cells secure the keratin tubules together
atropinemuscarinic antagonist
Parasympatholytic (blocks the receptor) , used to increase rate, reverse heart block due to increased tone of vagus nerve
How do host cells recognise pathogens
Pathogens express specific components that are recognised by the hosts as 'danger signals'Pathogen associated molecular patterns (PAMPs)The host expresses specific receptors that recognise PAMPsPattern recognition receptors PRRs
Pneumonyssus caninum - Dog nasal mitepathology, diagnosis, treatments
PathologyDepends on size of infestationSneezing / snufflingNasal discharge / bleedingDiagnosisFrom nasal swabs - adult mitesTreatmentsSubcutaneous selamectine
Starling force
Pc= CHP- hydrostatic pressure in the capillary.Pi= IOP- colloid osmotic pressure of the interstitial fluid.Both tend to force fluid out of capillary.Pi= IHP- hydrostatic pressure in the interstitial fluid.Pp= COP- colloid osmotic pressure of the blood plasma.Tend to suck fluid back into the capillary.Arterial end- filtration exceeds absorption, net production of interstitial fluid. At venous end- reabsorption exceed filtration.
Describe how the musculoskeletal structures of the bird are adapted for flight
Pectinous muscle is a large muscle beneath the supracoracoideus - the pectoral muscles are those who provide the down thrust of the humerus - the power stroke of flightThe supracoracoideus provides the upwards movement of the wing - the muscle is on a pulley aspect to the humerusThis means that the bird does not need to have an extremely large muscle which is heavy as the pulley system removes this need - more easy to flyThere are many holes in the bones of the birds skeleton to ensure that the flight of the bird is easyThe thorax of the bird is very rigid - this is to prevent the crushing of the thorax from the high power pressure of the pectoral muscles - unlike humans who thorax is dependent on our breathThe claw aspect of the birds have multiple different features for different needs eg graspingThe bird also has a form of a stay apparatus when perching meaning no energy is required when the bird is perched and resting
Describe how the musculoskeletal structures of the bird are adapted for flight?
Pectinous muscle is a large muscle beneath the supracoracoideus - the pectoral muscles are those who provide the down thrust of the humerus - the power stroke of flightThe supracoracoideus provides the upwards movement of the wing - the muscle is on a pulley aspect to the humerusThis means that the bird does not need to have an extremely large muscle which is heavy as the pulley system removes this need - more easy to flyThere are many holes in the bones of the birds skeleton to ensure that the flight of the bird is easyThe thorax of the bird is very rigid - this is to prevent the crushing of the thorax from the high power pressure of the pectoral muscles - unlike humans who thorax is dependent on our breathThe claw aspect of the birds have multiple different features for different needs eg graspingThe bird also has a form of a stay apparatus when perching meaning no energy is required when the bird is perched and resting
myotatic reflexes triceps
Percuss a finger/thumb which is pressing onto the tendon of insertion of the triceps muscleCauses - reflex extension elbow, increased tension in tendon, movement of skin over muscle belly
myotatic reflexes cranial tibial
Percuss muscle belly of cranial tibial - causes reflex flexion of the hock
myotatic reflexes extensor carpi radialis ECR
Percuss the muscle belly of ECR muscleReflex = extension of the carpus
haemotology
Performing a differential cell countObtain an accurate total WBC count by machine or manual haemocytometer - Cells x 10^9/LUse blood smear to count and classify 100 or 200 WBC calculate an absolute number for each type (10^9/L) from % and total white blood cell count
What types of atrial septal defects occur in animals?What are their impacts of oxygen delivery and cardiac function?
Persistent foramen ovale = doesn't close can close migraines and strokesAtrial septal defect= cause extra blood to overfill the lungs and overwork the right side of the heart. If not treated, the right side of the heart eventually enlarges and weakens. The blood pressure in your lungs can also increase, leading to pulmonary hypertension
XLD agar
Phenol red changes from yellow to red as pH changesselective growth medium used in the isolation of Salmonella and Shigella species from clinical samples and from foodIt utilizes sodium deoxycholate as the selective agent and, therefore, is inhibitory to gram-positive micro-organisms
G protein linked
Pheromones, hormones, neurotransmittersExample - cAMP, IP3Norepinephrine/epinephrine operates through thisBinding causing change which activates protein on inside which causes a second messenger system to be activated
function of the retina
Photoreceptors outer most layerretinal ganglion inner most layer Light has to travel through all layers to get to photoreceptors And then back across the retina to exit through retinal ganglion axons
what keeps airways sterile?
Physical barriers keep distal airways sterile and reduce the particles that get to the lower respiratory tractUpper respiratory tract is not sterile - nasal pharynx, tracheaIt gets cleaner going down due to cilia and secretions which are preventing excessive accumulation of organismsCommensal organisms colonise epithelia surfaces
Discuss how to investigate a lame horse
Physical examHistoryTrot up / gait assessmentLungingFlex joints - flexor testultrasonography/radiography/nerve block/MRI/synoviocentesis
where does enchondral ossification occur postnatally?
Physis/growth plate - longitudinal bone growthArticular epiphyseal cartilage complex (AECC)Cuboidal bonesOccurs during healing of unstable fractures - cartilage forms which is replaced by bone
List factors which aid adhesion
Pili/fimbraeAdhesinFlagellumCapsule
Give examples of avian specific problems relating to the musculoskeletal system
Pinioning - cutting off manus to prevent flight and brailing involves holding manus in flexed positon by leather straps
atlanto-axial joint
Pivot or trochoid joint Allow movement/rotation around axis Ce1 and Ce2 (atlas and axis) allows rotation Atlas as a tube and axis as a peg - allows rotateno joint
visceral vs parietal pleura
Pleura covering the surface of the lung is called visceral/pulmonary pleura. It is reflected around the root of the lung where it joins with the bronchi and becomes continuous with the costal parietal pleura. This in turn is continuous with mediastinal pleuraVisceral pleura = coats lungParietal pleura = lines thoracic cavity
Describe the location of the pleural cavity and mediastinum
Pleural cavity: lung has fluid outside- don't extend to sternum.Mediastinum:it contains the heart, thymus gland, portions of the esophagus and trachea, and other structures
Describe the radiographic appearance of pleural effusion
Plural effusion: "transudate", blood, lymph, exudate. Edge of lungs have fluid on outside.
process of erythropoiesis
Pluripotent stem cells, erythroblasts still have nucleus - reticulocyte and then final mature erythrocyte
How is technical quality of a thoracic radiograph assessed?PCCELA
Positioning- PinkCollimation- CamelsCentring- CollectExposure- ExtraLabelling/markers- LargeProcessing/artefacts- ApplesInspiratory or expiratory?- On Inspiration- not the end of the world but makes interpretation more difficult if not achieved
leads of ECG
Positive and negative electrodesThey are called limb leadsOne - RF and LF - positiveTwo - RF and LH - positiveThree - LF and LH - positive Earth lead on hindlimb
Pharmacological manipulation of contractility
Positive inotropes Causes phosphorylation of calcium channels Allowing faster calcium reuptake Sensitisation of troponin C to calcium Increases contractility
production and drainage of aqueous humour
Posterior chamber secretes aqueous chamberLeaves anterior chamberMost aqueous humour drains out the eye entering trabecular meshwork and drains into aqueous plexus and into Venus
lymph nodes function
Presentation of antigen to lymphocytes and immune response if necessaryLymph enters node by afferent lymphatics and leaves via efferent lymphaticsPacked with T- and B- lymphocytes, antigen presenting cells and monocytesImmune cells are monitoring lymph for foreign pathogens
what does constriction of arterioles cause to happen with the right ventricle
Pressure increases in 'circuit' supplying the lungsIncreased pressure generated in arterioles which is transferred to the pulmonary arteries which then ultimately impacts the right ventricle Increases in PA pressures increase within hours Changes in RV will occur within days to weekschanges in structure of blood vessels and heart seen - hypertrophy of the media of the arterioles, dilation of right ventricle hampers ability to flow into the lungs which results in right side heart failure
Explain the impact of inhibitors on the coagulation cascade
Prevents inappropriate clot formation. Tissue factor pathway inhibitor (TFPI), Antithrombin (III)- thrombin & factors IXa, Xa & Xia.
reduced oxygen inspired causing hypoxia
Problems with oxygen supply - kinked ET tubeLow atmospheric pressure - reduced oxygen in atmosphere When air is inspired it becomes humidified Therefore we have to account for the loss of saturated vapour pressure when inspired Amount of oxygen inspired is a lot less because of the pressuresHypoventilation - causes hypercapnia Extremely common especially in anaesthetised patient Partial pressure of oxygen in alveoli decreases and carbon dioxide partial pressure increases Due to us not breathing enough causes carbon dioxide accumulationBOAS
Golgi tendon organ describe function
Produce information from the tendonsLocated serially with muscle fibresBetter place to respond to tension
main functions of ciliary body
Produces and drainage of aqueous humour Maintains normal intraocular pressure Provides nutrition to lens and inner corneaAnchors lens zonules and provides accommodation - focussingConstitutes blood aqueous barrierProvides blood and nerve supply to anterior segment
function of tear film
Providing nutrients and oxygen to ocular surfaceProtects ocular surface from desiccation and bacteriaLubricates ocular surfaceProvides smooth and transparent ocular surface
Describe the mechanisms which occur and the systems which are activated during heart failure
R.A.A.S- salt/water retentionFluid builds up in vessels- especially veinsVenous pressure risesHigh venous pressure-> fluid is pushed out of veins-> congestion/oedema.But output and blood pressure are restored- usually have few weakness signs- blood pressure kept up, collapsed state is rare but would be severe and advanced heart failureADH- anti-diuretic hormone- water retentionNatriuretic peptidesAtrial stretch- atrial natriuretic peptide- now being used as diagnostic tests- markers of heart failure. Stimulates natriuresis- removal of salt and therefore water. Therefore reducing atrial stretch.
specific defences
Recognition of particles by immune system Passive immunity Lymph nodes/tissues Innate immune system Mucosal immunity Antibodies and lymphocytes
haemoglobin buffer system
Red blood cells are tightly packed with haemoglobin (Hb) and cytoplasm contains carbonic anhydraseRich in histidine residues and accounts for majority of the overall protein buffering capacity of the bodyCarbon dioxide into blood stream most into red blood cellsSome of the carbon dioxide binds with haemoglobinMajority goes into carbonic acid which mainly goes to hydrogen ions and HCO3- (bicarbonate ions)Hydrogen ions buffered by Hb which changes configuration of Hb molecules and releases oxygen into the tissues
Describe the mechanisms of arterial dilator drugs
Reduce afterload, increase output, reduce valve leakage, reduce work of the heart.
Pharmacological effects of benzodiazepines
Reduction of anxiety and aggressionSedation and induction of sleepReduction of muscle tone and coordination= diazepam and alprazolam they are effective after a single doseSide effects - memory impairment can cause irritability and aggressioneg alprazolam, lorazepam, diazepamactivate specific benzodiazepine receptor that facilitates inhibitory GABAergic transmission
Poutine reticular fomration
Region in the pons that is involved in regulating the sleep and wake cycle and filtering incoming stimuli to discriminate irrelevant background stimuli
functions of respiratory epithelium
Regulation of air flow by erectile tissueCleaning (cilia)Humidification (evaporator)Warming (variable blood perfusion)Protecting reflexes (sneeze reflex)
neurotropic spread definition?
Relating to the growth of nervous tissueFrom peripheral nerves nerve to nerve
what happens when we get to extreme preloads / what is the length tension relationship
Relationship lostIf we have a low preload we have limited cross over between actin and myosinIf they stretch further due to increased pre load - greater potential for cross bridge to occur leading to increased contractile forceIf over stretched sarcomeres it leads to a point where less ability for cross bridge formation so reduced contractile force
what is the effect of the PSNS on the heart and lungs?
RelaxationSlows heart rateBreathing slows down
how are ssDNA viruses produced?
Require active host DNA polymerase to replicate genome.These viruses can productively infect only dividing cells, where DNA polymerase is active. They then use host RNA polymerases to produce mRNA.E.g. parvoviruses, circoviruses
factors influencing ventilation
Resistance to flow in the airwaysLung complianceAlveolar surface tension
mechanisms limiting global ventilation
Resistance to flow in the airwaysLung complianceAlveolar surface tension
functions of paranasal sinuses
Resonating cavitiesInsulation / coolingLight weight constructionIncreased insertion surfaces - spaces for teeth
retinal detachment
Retina is strongly attached at only two pointsAround the optic discOra ciliaris retinae (peripheral retina)Detachment occurs between neurosensory retina and RPESystemic hypertension, e.g. geriatric catsCongenital, e.g. collie eye anomaly (inherited retinal disease)TraumaInflammationNeoplasiaComplication of lens luxation or chronic cataract
DNA variation
Ribosome sequencingMulti locus sequence typing MLSTProbe based testsPCR
Which chamber of the heart is enlarged in this cardiac radiograph:
Right Heart Enlargement- lateral: RA difficult to interpret. Increased sternal contact, apex should normally only be on the sternum.
lung lobes on positive contrast dorsoventral bronchogram
Right Lung Lobes:CranialMiddleCaudalAccessoryLeft Lung Lobes:Cranial- cranial, caudalCaudalIndividual lung lobes are not often seen, unless there is abnormal air filling due to disease- contrast between lobes.
Describe the positioning of dogs and cats for lateral thoracic radiographs
Right lateral recumbency (left side imaged)- heart, both laterals when looking for lung metastases- bottom lung collapses, top inflated.Put a wedge under the sternum easier to interpret. Center beam on back end of the scapular.
identification of leucocytes
Romanowsky stain effect - a mixture of 2 stains that give a third colour (purple)PurpleEosinOrangeAcidicStains basic tissue components orange (to pink)Components described as 'eosinophilic' or 'acidophilic'AzureBlueBasicStains acidic tissue components blue (to black)These components are described as basophilic
alveolar sac
Rotunda-like area on the end of the alveolar ductThere is usually a cluster of alveolar sacs at the end of one alveolar duct
sepsis
SIRS due to infection
shock
SIRS induced hypotension (reduced blood pressure) unmanageable by fluid resuscitation in association with hypoperfusion (low blood flow) leading to reduced oxygen level in organs/tissues (ischemia)
pericardium
Sac surrounding heartInner - visceral layer - surface of heartOuter - parietal layerNo significant lumen
Describe the formation of vertebrae - resegmentation?
Sclerotome become attracted to notochord/neural tube region and grow around them and meetResegmentation change - splitting of existing sclerotome and joining of neighbouring scleretomesas nerves come out from neural tube to myotome a fissure is formed in the sclerotomethe cranial part of one sclerotome and caudal part of other sclerotome fuses
What occurs to the valves during ventricular diastole?
Semi lunar valves closedMitral and tricuspid valves openBlood flows into ventricles
What occurs to the valves at the beginning of ventricular systole
Semi-lunar valves openBlood is ejected from the ventricles
What occurs to the valves at the beginning of ventricular systole?
Semi-lunar valves openBlood is ejected from the ventricles
Cranial nerve IX - Glossopharyngeal test
Sensory, taste (posterior 1/3)Motor to tongue (extrinsic muscle)Stylopharyngeus muscleMotor to pharynxOften see horses with tongue protruding between the incisors
coagulase test
Separate coagulase positive / negativeStaphylococcus aureus and also separate other groups of non-coagulase positive staphylococci S. epidermidisCoagulase is often associated with virulence but some coagulase negative strains can cause disease
AV cushions
Separation between atria and ventricles at red arrow beginsCardiac jelly and blood flow triggers developed atrioventricular endocardial cushionsForms a barrier/shelf so separates atria and ventriclesUltimately form papillary mm, chordae tendinea, growth of mesenchyme and AV valves
what is typing?
Separation of bacteria within the same species is typingTyping allows linkage of bacteria derived from same lineage or sourceTyping asks are the bacteria from the same lineageIt uses common features that can vary subtly within species due to drift between separate populationsPhysical methods for typing are being replaced by molecular typing
Describe the potential causes of alveolar pattern
Should be black- air filled , changes in pattern caused by alveoli being filled with:Fluid- oedema, blood, pusCellular debrisNeoplastic infiltrateOr lung lobe collapse
what does blood oxygen content of blood show? and how is this measured
Shows effective lung functionShows effective ventilationAssessed globally by Mucous membrane colour Nice and pink is good oxygen delivery Pulse oximetry and Blood gas analysis
shunt 3: ductus arteriosus
Shunts blood in pulmonary artery straight to descending aortaPressure differential between lungs and lower body streams flow back to placentaAllows equivalent ventricular function in fetus - helps develops ventricular musculature and vasculatureHelps blood not to go into the lungs but pulmonary artery and into aortaclosureFunctional closure in mins to hoursAnatomic closure may take 2-7 daysIf closure does not occur, ventricular septal defect = patent ductus arteriosus Relatively common condition, non life threatening, reduces efficacy of heart
shunt 2 - foramen ovale
Shunts oxygenated blood straight through RA to LA through foramen ovale due to the high flow of the bloodPressure difference across FO keeps it open in fetusPatency maintained by high blood flowclosure= functional closure quick - hours= anatomic closure is slow - weeks/years with a small opening persisting in about 25% mammalsFailure to close results in atrial-septal defect and hole in heart
acid fast
Similar to gram positiveGenetically linkedSingle membrane, thick cell wall, mycolic acids - waxy compounds which are crosslinked with the cell wall - makes it harder for things to penetrate One group called mycobacteria
ventricular premature complexes
Site of origin is within the ventriclesRhythm is irregularWide and bizarreQRST complex interrupts rhythmSpread through myocardium not conducting tissueUsually the underlying NSR is undisturbedQRST unrelated to P wavesQRST complex voltage is usually large
neutrophils histology
Size 12-15 micrometres Double size of erythrocyteLobulated nucleus (2-4 lobes)Pale pink or light blue cytoplasmbelow = a banded neutrophil does not have segmentation of the nucleusThey are young neutrophils
mean arterial pressure MAP affecting blood pressure
Size and shape of arterial pulse wave - related to stroke volumeSpeed of this wave - fast in small arteriolesMAP will increase during exerciseIt is different in different species
MSK diseases dogs
Size/weight - biomechanical forcesGenetic conformation - especially at extremesActivity - high impact/biomechanical forcesDiet - excess/insufficient nutrient intakeObesityTraumaAgeing changesDamage to blood supply to femur causes epiphysis to die - Legg-Calve-Perthes disease
The atrioventricular node what does it do
Slows conduction through the heart of the action potential - allows time for ventricles to fill completely before contraction Small pause in between atrial and ventricular contraction
angiostrongylus vasorumindirect life cycle
Slugs are intermediate hostFrogs are para hostDogs are definitive hostZoonotic - animal to human transmission
poiseulles law
Small changes in vessel diameter lead to large changes in resistance and pressureSo if blood flow (cardiac output) stays the same and resistance increases then pulmonary arterial blood pressure will increaseBecause flow = pressure/resistance
Identify the main features of the musculoskeletal system of reptiles
Snakes have a large number of vertebrae and each vertebra have ribs attached to it - the ribs are not anchored to the sternum which allows free movementNo pectoral girdle they have an attached muscle that flexes and extends spurs used to hold female while matingZygosphene and zygantrum in the snake vertebrae are processes that fit together in order to make sure that the snake vertebrae remain together even when the snake is moving this ensures that no damage occurs to the spinal - cord and the snake is still able to move freely
identify the main features of the musculoskeletal system of reptiles?
Snakes have a large number of vertebrae and each vertebra have ribs attached to it - the ribs are not anchored to the sternum which allows free movementNo pectoral girdle they have an attached muscle that flexes and extends spurs used to hold female while matingZygosphene and zygantrum in the snake vertebrae are processes that fit together in order to make sure that the snake vertebrae remain together even when the snake is moving this ensures that no damage occurs to the spinal - cord and the snake is still able to move freely
defence of lungs = sneezing/coughing
Sneeze ReflexUpper respiratory tractClears nasal passagesCough reflexLower respiratory tractClears trachea and bronchi= this is to remove foreign objects or irritants
control of viral gene expression
Some viruses regulate gene expression very tightlyLatency helps to explain pattern of disease eg intermittent or delayed
causes of glaucoma
Something going wrong in drainage of the eye
spleenred pulp functionwhite pulp function
Specialised lymph node for blood borne antigensPart of vascular blood system - efferent lymphatics (all pathogens presented in blood)Red pulp : Filters blood and foreign pathogens Removes defective erythrocytes and platelets Stores erythrocytes and plateletsWhite pulp: Macrophages and antigen presenting cells and ageing erythrocytes T and B lymphocytes within the area Immune response to foreign pathogens that are presented through the blood
what is cartilage?
Specialized form of connective tissueSupports and growth template for long bone formationNon vascularizedNon innervated
retina blood supply differences in retina
Species differentDifferent arrangement of blood vessels affecting appearance of fundusHolangiotic = retinal blood vessels supply whole retina eg dog cat cow, sheep goatPaurangiotic = retinal blood vessels supply a small focal area of retina eg horse
non-lobulated lung
Species that have non-lobulated lungs also have a collateral ventilation - bronchioles that are running in parallelThese channels are normal airways but help to maintain normal ventilation-perfusion relationships in the face of hypoxia So minimise pulmonary vasoconstriction
selective media
Specific nutrients which are beneficial to a particular type of bacteria which you are trying to cultivate, alongside inhibitors for any unwanted bacteria speciesEnteric bacteria are often resistant to bile salts, so they can be added to dishes when intestinal bacteria are desiredAntibiotics can also be used as some bacterial groups will be resistant to certain strains
Describe how the severity of heart disease is assessed
Stage A- patients at high risk of heart disease but have no identifiable structural disorder of the heart- breed associated disease- CKCS- degenerative valve disease, Irish wolfhounds at risk of DCM etc.Stage B- patients with structural heart disease (e.g. murmur), but no clinical signs ("occult" disease).Stage B1- asymptomatic patients with no radiographic or echocardiographic evidence of cardiac remodelling.Stage B2- asymptomatic patients with radiographic or echocardiographic evidence of left-sided heart enlargement.Stage C- mild-moderate- patients with past or current clinical signs of congestive heart failure associated with structural heart disease. Evidence of limitedexercise tolerance- mild. Progressively worsens. Signs evident with mild exercise- moderate. Differentiates patients requiring hospitalisation.Stage D- advanced- obvious clinical signs with minimal exercise- progressively worsens. Obvious clinical signs at rest- progressively worsens- death. Patients with end-stage disease with clinical signs of heart failure that are refractory to ''standard therapy''.
Cardiac output affecting blood pressure
Starling Effect - increasing stretching of heart muscle from increased pre load we will increase contraction - increasing stroke volumeStroke volume x heart rateSympathetic stimulation : increase heart rate and force of contractionParasympathetic stimulation : decreases heart rate and slight decrease of force
stuporous
State of unconsciousness with absence of response to any environmental stimuli including pain
confused and distorientated
State of unconsciousness with reduced responses to external stimuli but can be roused by a painful stimulusAlert, with a normal response to environmental stimuli
strabismus
Strabismus describes abnormal static position of the eyeThis can be predictably generated by lesions affecting the III, IV and VI cranial nerves
pilli / fimbriae
Strands of protein attached to bacteriaMade of pilin peptide subunitsConsidered to function for adhesionSome are virulence factorsSome bind to sugars on host cells to aid attachmentSome involved in biofilm formationSpecific F-pili involved in conjugation
cornea
Stratified epithelium and basement membraneCollagenous stromaDescemet's membrane - basement membrane of the endothelium
Describe the process of secondary haemostasis
Strengthening and reinforcement of the platelet plugFormation of a stable fibrin clotInvolves coagulation factors (e.g. factor VIII), several factors are synthesised in the liver in a process that requires vitamin K
the pharyngeal wall
Striated muscles Constriction and shortening Rostral - palatopharyngeal Middle - hypopharyngeal Caudal - thyropharyngeal All insert on roof of pharynx Important in passage for food Dilation Single muscle Stylopharyngeus caudalisfunctions Swallowing - deglutition Soft palate elevated Palatopharyngeal arch constricts Hypoid apparatus Pulls larynx forward Epiglottis pulled back to protect larynx
What is the relationship between end-diastolic volume and the magnitude of stroke volume?
Stroke volume is the end diastolic volume - the end of systole volumePreload - contractilityDependent on the amount of blood in the ventricles at the end of diastole and the amount of blood left in the ventricles at the end of systole
stroma and bulbar conjunctiva arrangement
Stroma have extensive vascular and lymphatic suppliesBulbar conjunctiva overlies sclera = we will see finer branching conjunctival vessels but these overlie larger episcleral vesselsInflammation in the eye can cause the larger vessels to appear visible
Eosinophis
Strongly associated with allergy, parasites and fibrosisRarely found in healthy bloodSpecific granules contain:Major basic proteinEosinophil cationic proteinEosinophil peroxidaseEosinophil derived neurotoxinEnzymes
what causes dysrhythmias
Structural cardiac disease (actual problem with heart eg scar tissue), drugs, toxins, metabolic diseases/electrolyte imbalance, systemic disease - sepsis, neoplasia, sympathetic tone - increased epinephrine release eg pain and fear
physiological dead space
Sum of anatomical dead space and alveolar dead space
Explain the vascular supply to the brain including both venous and arterial structures
Supplied by 5 main pairs of vessels:Rostra cerebral arterial - supply the medial aspect of cerebral hemispheresMiddle cerebral arteries - supply lateral and ventrolateral aspects of cerebral hemispheresCaudal cerebral arteries - supply occipital lobesRostral cerebellar arteries - supply rostral aspects of cerebellumCaudal cerebellar arteries - supply caudal and lateral aspects of cerebellum They are all joined by the arterial circle
aqueous humour
Supplies nutrients and remove waste from avascular tissues of the eye Cornea Trabecular meshwork Lens Anterior vitreousMaintains optical clarity of eyeComposition - 98% water, protein, ascorbate, amino acids, oxygen, glucose
List the vascular supply to the distal limb
Supply basically from median artery and divides downAxially artery - brachial artery - medial artery - medial palmar - medial and lateral palmar digitalKnow where they are
basophil
Surface IgE receptorSpecific granules : heparin, histamine, leukotrienes, lysosomesAssociated with parasitic infection and allergyVery rare in bloodRecruited into tissueMost important function is in immediate type hypersensitivity = cause of allergy
serous membrane - serosa
Surface of inner wall of body cavity is lined by a serous membraneSingle layered flat epithelium with thin underlying connective tissueMembrane is named pleura in thoracic cavity and peritoneum in the abdominal and pelvic cavities
suspensory apparatus
Suspension of the pedal boneCollagen fibre bundles between pedal bone and inner aspect of the claw capsuleSuspend the weight of the whole animalThe supportive cushion system supports the pedal bone and fat cylinders under the pedal bone
Describe the fate of inhaled particles within the upper respiratory tract
SwallowingTrapped in mucus and transported via Mucocilary escalatorStimulation of receptors/reflexes : sneeze or cough or glottis closureKilledStimulation of immune responses/antimicrobial agents in mucus / secretions
what are the functions of biological rhythms?
Synchronises our activity with external environmentExternal synchronisation - biological clocks internal physical systems allowing organisms to synchronise with rhythms of nature such as cycles of dayInternal synchronisation - maintain temporal organisation of endogenous processes by circadian systems
Describe methods of assessing synovial pathology
Synovial fluid is removed by synoviocentesis at the four different aspects of the distal limb it can be removedThe colour of the fluid is assessed - should be straw colour/faint yellow with a fluid consistency and be able to stretch across your fingersThe protein level should by 25g/l so 2.5 for decimetre - anything above or change in colour shows infection - red/pink shows red blood cells have entered fluid and there is likely to be a rupture present
recognising different antigenic shapes
T helper cell with CD4+ expressed on surfaceCD3+ element is embedded within T cell itself2 chainsAlpha and beta chainAssociated with the CD3+ glycoproteinT cell receptor - recognises peptide of a pathogenTwo regions: Regions attached to cell surface towards T helper cell end - constant region Region further to right side need antigen/peptide - variable regionCD3+ is used to distinguish a T cell over B cellTransmitting information to generate cytokines and further responses - recruitment / differentiationOn antigen presenting side is a MHC-2 = another type of receptor that is associated with antigen presenting cell on how it presents peptide of processed pathogenBinds to T cell receptorAllows it to recognise antigen on complex
How do TLRs not interact with commensals in the body?
TLR receptor expression on basal surface of epithelial cells but not on apical surface that is in contact with the gut lumen and the commensal bacteria.Infection with pathogenic bacteria- barrier injury. TLRs on basal surface come in contact with bacteria or their PAMPs, inflammation.
What is the structure of TLRs?
TLRs are membrane spanning receptors.Extracellular- leucine rich, recognises PAMPs.Cell membrane- transmembrane domain.Intracellular- toll/IL-1 receptors for signalling.
Describe supraventricular premature complexes
TachycardiaA premature P wave (P') interrupts the normal P wave rhythmP' wave then causes an early QRST complex.QRST complex looks normal
Describe supraventricular tachycardia
TachycardiaRuns of more than three consecutive supraventricular premature complexesRhythm is regularSite of origin is within the atria/junction, outside of the SANIt may be sustained (>30s) or non-sustained (<30s)P'-P' interval is regular, as is P'-R interval if every P' wave is conductedQRS is usually normal
what are the presenting signs of hypoxia
Tachypnoea Increased respiratory effort, tachycardiaPatients unable to compensate for hypoxaemia Exhaustion, neurologic or neuromuscular diseaseCyanosis Appearance of bluish/purple discolouration of the skin or mucous membranes due to the tissues near the skin surface having low oxygen saturationHypercapniaAn elevation in the carbon dioxide in arterial blood (PaCO2) above the normal range of 35-45mmHgCommonly caused by hypoventilationOther causes : hypothermia, respiratory depression, lung pathology, increase in metabolic carbon dioxide production
why would you take swabs?
Taking swabs from upper respiratory tract Is common techniqueEssential diagnostic tool for many different upper respiratory tract infectionsDifferent pathogens require different swab sites
The roles of each part of conducting zone?bronchi
The Bronchi Are Passageways That Bring Air In and Out of the Lungs. The tubes of the primary bronchi branch off from the bottom of the trachea. These branches subdivide further into secondary and tertiary bronchi and then into the bronchioles.
Explain the effects of exercise and training on the cardiovascular system
The aim is to increase the blood flow to the limbs (or exercising muscle)Achieved by : Increase cardiac output - product of heart rate and stroke volume Pressures can change but due to peripheral vasodilation the overall blood pressure doesn't change too much during exercise Increase oxygen carried in blood - more o2 or red blood cells Horses release of red blood cells from the spleen increases oxygen carriage (but also velocity) Redistribute blood flow - ie to muscles needing it Not GIT
Describe the fate of each of the embryological aortic arches.
The aortic artery divides into the right and left dorsal branchesEach branch feeds into a set of arches which are unique to the embryo Most higher vertebrates have 6 pairs of aortic archesArches 1 & 2Arches 1 and 2 degenerate completely, the dorsal Aorta that runs between arches 3 and 4 degenerates on both the left and right sides.Arch 3The third arches form the internal carotid arteries.Arch 4The left fourth aortic arch contributes to the arch of the aorta. The right fourth aortic arch forms the proximal segment of the right subclavian artery.Arch 5The fifth aortic arches are never present in the mammal.Arch 6The proximal segment of the right sixth aortic arch forms part of the right pulmonary artery while the distal segment atrophies. The proximal segment of the left sixth arch forms part of the pulmonary artery while the distal segment forms the ductus arteriosus.These changes occur in the third and fourth weeks of gestation, at which point the foetal circulation begins to resemble that of the adult.
why may bacteriology from swabs not be conclusive?
The bacteria of the respiratory tract :Exist in mixed populations and may be present whether disease is there or not so therefore bacteriology from swabs may not be conclusive
factors that can impact on host defence
The balance can be tipped in favour of disease by: environmental factors, intercurrent disease, environmental change
structure of vascular tree
The blood is sent "in parallel": each tissue receives fresh blood from the heart and not from other tissues
Compare the skeleton of the distal limb between different species
The different species have difference in ray patternsThe cow and pig have different numbers of meta carpal bonesThe dog has 1-5 and the horse has 2-4 the ox 3-4 has and the pig has 2-5
Describe the functional groups of muscles that control laryngeal function and their effect on airway resistance
The extrinsic laryngeal muscles (the thyrohyoid and the sternothyroid) change the position of the larynx in the neck by raising or lowering the thyroid cartilageDuring respiration the larynx widens the diameter of the airway via abduction of the true vocal folds, exponentially decreasing airway resistance while maximizing flow = by the intrisic laryngeal muscles
oestrus ovis (sheep/goat) = bot fly
The fly is like a bee in sizeLarval stage will mature to maggot and will live mainly in sinuses in sheepCausing irritation as bodies covered with minute spines and obstruct airwaysThey drop on the ground forming pupae and another fly will form from thisMyiasis - infection of live tissue with maggotIt is less common due to antiparasitic drugs like ivermectinNasopharyngeal MyiasisFly deposits larvae in or around nostrils of hostPathology associated with mucous membranes in nasal cavity and sinuses - ' Strike ' in rabbits and sheep
strabismus
The inability to align both eyes, often referred to as 'cross eyed'
suspensory apparatus
The interosseous in the horse is also known as the third interosseous muscle as third digit or the suspensory ligament (SL)Forms part of the suspensory apparatus of the fetlock joint
The roles of each part of conducting zone?larynx
The larynx (voice box) is the area that connects the throat to the windpipe (trachea). Without it, we would hardly be able to sing or speak. It also keeps food and drink out of the windpipe.
Consider two major mucosal sites that have a highly vascularised blood supply and pose routes to infection of the blood and then systemic sites ?
The lungs alveoli Infection in the lung may be a route to get into oxygen supplyThe gastrointestinal tract Blood supply is there for the uptake of nutrients Infection of the mucosa of the GI tract posses a risk for further systemic infection Here the blood goes to the liver and spleen which is why we get a few infections from GI tract which spread to liver and spleen
Explain the function of the Na+/K+ ATPase, sodium, potassium and calcium channels
The membrane is very permeable to Na+Movement of potassium out of the cell is due to the force of diffusion as potassium is concentrated within the axon - electrostatic pressure forces potassium insideNa+ diffuses into cell due to negative charges in axonNaK pump pushes sodium out of the axon continuously (energy by ATP)A smaller amount of K enters cell in exchange for sodium
What is the effect of osmolarity/water potential on bacterial growth?
The membrane of bacteria is semi-permeableBacteria need to balance their water potential to excessive movement of water in or out of the cell.Bacteria accumulate or loose solutes to balance the water potential across the membrane.Bacteria prefer to maintain a slight positive pressure- an inflow of water which is resisted by the cell wall.
Construct a logical approach to performing nerve blocks in the horse
The nerve block should be carried out palmarly first and then abaxially15 minute wait time after each nerve block injection to ensure sedation is fullIf the lameness is still present at palmar but redundant at abaxial then the lameness can be isolated to a site below the fetlock joint but above the back of the foot.
physiological nystagmus
The oculovestibular response demonstrates a physiological nystagmus.If the head is rotated from side to side there should be an induced nystagmus visible rather than just "doll's eye" movement of the eyes with the head.
nasal vestibule
The opening of the nasal cavity Contains the opening of the nasolacrimal duct Visible just inside ventral surface Receives nasal gland secretions in dogs
palpebral response
The palpebral response can be elicited by gently touching the region of the medial canthus of the eye and demonstrating an active blink.Afferent nervous supply is the TRIGEMINAL nerveEfferent nervous supply is the FACIAL nerve
effect of the SNS on the lungs
The parasympathetic nervous system (PNS) releases the hormone acetylcholine to slow the heart rate.
Explain how the structure of the equine foot relates to its weight-bearing function
The pedal bone is suspended by the suspensory ligament and fat cushioning below P3
The roles of each part of conducting zone?the pharynx
The pharynx acts as a passageway for food on its way to the stomach and for air on route to the lungs. The mucosal epithelium in the pharynx is thicker than elsewhere in the respiratory tract as it has to protect the tissues from any abrasive and chemical trauma caused by food
portal systemmain advantage of this
The portal system : few organs are connected 'in series' they obtain their blood from the venous outflow of another organ so 'second hand' bloodThe main advantage to this is transports a solute from one place to the other without dilation in the general circulation
ferritin
The primary intracellular iron - storage protein keeping iron in a soluble and non-toxic form which releases iron in a controlled fashion. It is a buffer against iron deficiency and iron overload
primitive development vs later development
The primitive development : atria, SA valves, AV valves, semilunar valvesLater development - two ventricles, truncus arteriosus into Ao and PA and vena cavae
what happens when a base is added to the body
The respiratory rate is reduced and carbon dioxide is retained
mediastinum structure and contents
The space between the left and right pleural sacsMidline of thorax, extends from the thoracic inlet to the diaphragmContains = heart, thymus, portion of oesophagus, trachea, blood vessels and nerves
What parts of the brain stem control pain pathwyas?
The spinothalamic tract for pain and temperature sensationAll information relayed from the body to cerebrum and cerebellum traverse the brainstemThe ascending pathways from body to the brain are sensory pathways
the theory of recapitulation fish, amphibians and reptiles
The stages of the mammalian heart goes through during embryological development are evident in the CV systems of fish, amphibians and reptiles
outline the three stages of haemostasis
The stages run one to the other and feedback to each other.Primary- initial response to endothelial damage, local vasoconstriction, formation of the platelet plug.Secondary- strengthening and reinforcement of the platelet plug, formation of a stable fibrin clot.Tertiary- removal of fibrin by fibrinolysis, restore vessel patency (i.e.open/unblocked).
what is exercise physiology
The study of short and long term adaptations In response to exercise that can encompass physiology of : the cardiovascular and respiratory systems, muscular systems, biomechanics, thermoregulation, haematology, nutrition and water
swinging light test
The swinging light test allows you to test the integrity of both the direct and consensual PLR pathways in an easy manner.In a darkened room swing the light rapidly from eye to eye stopping for several seconds on each eye.
what is the sympathetic nervous system effect on heart
The sympathetic nervous system (SNS) releases the hormones (catecholamines - epinephrine and norepinephrine) to accelerate the heart rate. Increased cardiac contractility, reduced venous capacitance and peripheral vasoconstriction
Describe the main features of the pad and claws of the dog and cat
The toenail, or claw, emerges from the end of each toe. The foot also has cushiony pads for each toe and two larger pads farther up the pawRough surface to pads. Dogs' toenails have a blood supply or quick, but the end of the nails are dead tissue. Dogs perspire through their pads. Pads provide both traction and shock absorptionDogs have scent glands on the bottoms of their feet that allow them leave a mark that can be seen and sensed by other animals.A dog's claws are fairly strong. They help the dog to run and maneuver, to dig and they do offer some protection. catsThere are five digits, or toes, on each front foot, and four on each back foot - dewclaws on front which is useful for huntingSweat comes from cat paws if stressed there not great for cooling the body downAct as shock absorbers and sensors as have more many nerve receptors
Describe the main features of the pad and claws of the dog and cat
The toenail, or claw, emerges from the end of each toe.The foot also has cushiony pads for each toe and two larger pads farther up the pawRough surface to pads. Dogs' toenails have a blood supply or quick, but the end of the nails are dead tissue.Dogs perspire through their pads.Pads provide both traction and shock absorptionDogs have scent glands on the bottoms of their feet that allow them leave a mark that can be seen and sensed by other animals.A dog's claws are fairly strong. They help the dog to run and manoeuvre, to dig and they do offer some protection.catsThere are five digits, or toes, on each front foot, and four on each back foot - dewclaws on the front which is useful for huntingSweat comes from cat paws if stressed there not great for cooling the body downAct as shock absorbers and sensors as have more many nerve receptors
Nasotracheal Arthropods of Animals
The tongue worm - Linguatula serrataThe bot fly - Oestrus ovisThe nasal mite - Pneumonyssus caninum
The roles of each part of conducting zone?trachea
The trachea serves as passage for air, moistens and warms it while it passes into the lungs, and protects the respiratory surface from an accumulation of foreign particles.
umbilical vein fetal role and remanant
The umbilical vein carries oxygenated, nutrient-rich blood from the placenta to the fetus,Fibrous cord called the round ligament of the liver - ligamentum teres hepatis
Describe the components (epidermal-dermal and endochondral) of the chelonian shell and its relationship to the axial skeleton?
The vertebral column forms the under the surface of the carapace it is made up of dermal and endochondral bone - metabolically active with blood and nerve supply, turtle shell attached to axial skeleton it is formed of scutes which are the epidermis
retroviruses - group VI
The viral RNA is reverse transcribed into a complimentary DNA cDNAThis integrates into the chromosome of the host cell by viral integrase enzyme This is termed proviral DNAThe integrated DNA then produces RNA and protein using normal cell machinery
anatomical dead space
The volume of the conducting airways not available for gaseous exchange
three rules for paranasal sinuses
There are seven individual sinusesAppreciate that all paranasal sinuses drain via a common ostium - the single drainage angleUnderstand that the seven sinus spaces are arranged in two groups which drain via their own individual nasomaxillary apertures2 rostral group5 caudal group
Anatomy of the ribs
There is a dorsal bony part and a cartilaginous ventral part articulating at a costo-chondral junctionHead with 2 articular facets (for articulation with vertebrae)NeckTubercle with facet (for articulation with transverse process of the more caudal vertebra)True ribs - articulate directly with the sternumFalse ribs - articulating indirectly through connection of the cartilage with that in front - costal archDog = 13 (9 sternal, 4 asternal), Cat = 13, Cow = 13 - 8S,5ASternal
Describe the differences in the great vessels of the heart in the pig compared to the dog
There is a left azygous vein which branches off the caudal vena cava.The left and right common carotid arteries branch later off the brachiocephalic trunk resulting in a section of the brachiocephalic trunk called the bicarotid trunk.
palmar digital nerve blockwhat nerve are these branches ofwhat are the palpable landmarks for this techniquehow should you check you're not in a vesselwhat structures are desensitised with this block ?
These nerves are branches off of the median nerve, which splits in themedial and lateral palmer nerve respectively, and then once it reachesthe digits it is termed as the dorsal and medial digital branches.The vascular bundle as well as the vein can be palpated in the pastern region abaxial to the flexor tendons.Aspiration before injection; attempt to suck some blood back through the needle and if there is none then it is successful.All structures of the hoof aside from the distal coronary band.
Abaxial sesamoid nerve blockWhat nerve are these branches of?What are the palpable landmarks for this technique?What structures are desensitised with this block?
These nerves are still branches of the median nerve, specifically the medial palmer nerve again.The vascular bundles and associated nerves can be palpated over the pastern joint with the sesamoid bones as they run over their abaxial surface.Structures below including the digits are desensitised, excluding the dorsal aspect of the pastern.
benzodiazepines (BZDs)
They activate a specific receptor that facilitates inhibitory GABAergic transmissioneg alprazolam, lorazepam, diazepam and oxazepamenhances the response to GABA as it facilitates the opening of GABA-activated chloride channels
classification of viruses
They are grouped together based on similarity of genome sequence
What are toxins?
They are proteins formed as a precursor then cleavage by a proteases lead to activationThey are defined by antigenic typesSome target species correlation for toxin antigen typesPotentially fatalThe toxins act at very low doses
Specify the anticonvulsant drugs mainly used in the treatment of epilepsy in small animalsDrugs with Increased inhibitory function
They restore the balance predominantly by facilitation of inhibitory activityBenzodiazepine, barbiturates Potentiates endogenous GABAVigabatrin GABA transaminase inhibition causing GABA build upGabapentin Triggered GABA release from presynaptic terminalBromide Increased hyperpolarization - ion competition with chloride through channelsImepitoin Partial agonist at GABA-A receptor
What is the role of autorhythmic cells
They spontaneously generate APs and undergo slow depolarization until threshold is reached - these occur most rapidly in the SA nodeMonocytes can be divided into working cells with resting Vm or pacemaker/autorhythmic cells with unstable VmVm = membrane potential
manifestations of osteochondrosis
Thickened cartilageRadiographically evident defect in subchondral bone contour as can't see cartilageMay heal on its ownIntra-articular cartilage fragments (OCD)May ossify within the joint after separationSubchondral bone cystsMay follow on from ischaemic chondronecrosis lesionCan also be secondary to trauma
Describe the radiographic appearance of interstitial pattern in the lungs and the two types
Thickening/infiltration of supporting tissues.Diffuse (unstructured/fine structured)- all tissue- fibrosis (old age), interstitial oedema, interstitial haemorrhage, under-inflation/under-exposure.Nodular- neoplasia, metastatic disease, tumours- mist- can still see the outlines of the cardiac silhouette and lungs. Cancerous cells arrive in interstitial tissue and will show few respiratory signs.
Describe the concept of upper and lower motor neuron lesions
Thinking of UMNs as central motor neurons and LMNs as peripheral motor neurons may facilitate understanding as to where lesion is sited from what dysfunction has been caused neurological RATSIGN Reflexes, Atrophy and ToneUMN reflexes - normal to increased, atrophy - disuse: mild generalised, tone - normal to increasedLMN reflexes - decreased to absent, atrophy - neurogenic : severe, specific muscles, tone - decreased to absent
competitive antagonist
This binds to receptor in the agonist binding pocketSurmountableReversibleAffectively blocking agents
what do chemical signals that are relased by cells that have been damaged by injury or invasion do?
This causes dilation of local blood vessels Increases the blood flow to the injured area Causes the redness and heat associated with inflammation Makes it an unfavourable environment for microorganismsEg histamine, prostaglandins and cytokines
what is agar
This is a solid culture medium which fixates the bacteria so they can grow in separate colonies. It also contains various nutrients which are essential for bacterial growth.Contains organic nitrogen, vitamins, carbohydrates, nitrogen and salts
perfrom a musculoskeletal examination of the equine distal limb
This is all about flexing and extending the specific joints of the horse whilst being careful of your safety and the horses pain levels. It is used frequently in lameness examination particularly flexion tests where the horses joint eg fetlock is held in a flexed position for roughly 30-60 seconds and then put down gently and immediately followed by trotting up the horse. This will give clearer recognition of lameness as it will be more visible
how would you isolate to single bacteria-isolates on a solid media?
This is requires to be able to fully describe a bacterium.It is carried out on sterile media using aseptic techniques and the loop should be flamed.
erythrocyte breakdown
This is showing erythrocyte breakdownThe body tries to recycle as much products as possiblePhagocytosed by the macrophage and broken down into globin and haem partAmino acids are then returned to blood streamBilirubin excreted in bileIron for production of erythrocytes
What parts of the brain stem control respiration?
This is within the lower half of the brain stem as the respiratory centre is located in the medulla oblongata
M mode ultrasound
This measures movement along a single plainSingle plan against TIMEUsed to assess cardiac function Contractility Valve movement
fibrous cardiac skeleton
This separates atria and ventriclesThey are electrically isolated through each other - only way through is via AV bundleOssa cordis in some species Bits of fibrous skeleton ossify getting a bone
Most important tests in potentially septic foal?
Thoracic radiographyMaternal antibody transfer testBlood culture for bacteria
major fetal vessels and what do they do
Three key shunts Ductus venosus Foramen ovale Ductus arteriosusa passage or anastomosis between two natural channels such as blood vessels
three to five components of frontal sinus
Three to five components:Unconnected drain into ethmoidal regionCattle (5):One larger caudal compartment (green)leads to cornual process and pneumatises the horn.Dogs (3):Lateral compartment largest.May include the zygomatic process.Pig:Very extensive cavity.
Describe tests used to assess tertiary haemostasis
Thrombin clot time- assesses the ability of added thrombin to convert fibrinogen to fibrin. Tertiary haemostasis.FDPs/D-dimers- latex agglutination test, tertiary.
Describe the disorders of primary haemostasis
Thrombocytopenia- abnormally low platelet count- decreased production, increased destruction/consumption. Reference: 150-400 x109/L (dogs), <100: thrombocytopenia, 50: haemorrhage may beinduced- injury/surgery, <30: spontaneous haemorrhageThrombocytopathy- abnormal platelet function, e.g. von Willebrand's disease- deficiency in von Willebrand factor- more common in some breeds such as Rottweilers, might want to test with BMBT prior to surgery.Vascular defects
vascular ultrasound
Thrombus in the jugular veinMaturing and developingNormal blood is more greyDependent on flow speed
thymic education
Thymic educationBegins during foetal lifeContinues for first couple months of lifeThymus involutes (shrinks) = the lymphoid tissues become replaced by adipose and connective tissue This displaces a lot of lymphoid tissue so thymus is no longer active for thymic education
owl hearing adaptations
Tightly packed rim of facial feathers collect and direct sounds to external auditory meatusLeft and right external auditory meatuses are different size and shapes helping the nerve system localise soundsHearing Asymmetry enables precise pinpointing of prey Intensity and timing of sounds Horizontal and vertical planes of sounds established
What is the function of the cardiovascular system?
To deliver oxygenated blood to the tissues and to remove carbon dioxide
toxocara
Transmission can happen in utera from placenta to unborn pups or suckling milk or by ingesting larvated eggParatenic hostHigh zoonotic infection - human are accidental host and non-permissive host can cause ocular larva migrans
Define the functional role of the heart in the mammalian circulatory system and the major anatomical features of this organ that ensure optimisation of that role
Transport = Nutrients, waste, oxygen and carbon dioxide, heat and hormonesProtective = Carries WBC and IgHomeostasis = pH, ions, fluid volumePressure
normal ECG dog - P wave
Travels towards apex of the heartPositive deflection within leadsMore lead twoOnce atrium have depolarisedConduction gets conducting through AV node through bundle branches and then into the Purkinje fibres= Has to happen in normal manner to give normal depolarisation and contraction of myocardium
what has increased bovine lungworm in the UK
Treatment is anthelmintic treatment eg ivermectinIncreased reliance of anthelmintics instead of vaccination compromises the build up of immunological responsesSurvival of L3 on pasture due to climate change
true lungworm vs nontrue longworm
True lungworm: residing tissue for adults are lungs - find their habitat in the lungNontrue lungworm: worms which have only a lung phase but which not lungworms - residing tissue for adults are not lungs (commonly intestine)
turbinates
Turbinates - further subdivisionsDelicate scrolls in three groups :Ectoturbinates Within the frontal sinus 6 in dogs, 20-30 in horsesEndoturbinates In nasal cavity , 6 Attached to cribriform plate caudallyMaxilloturbinates In nasal cavity , paired, attached to wall of maxilla Forms the ventral concha
VQ mismatch consequence
Two different areas of the lungTop part is an area of high VQ ratioAnd the bottom part of low VQ ratioWhen blood splits into the area it splits unevenlyLarger amount goes through the area of low VQThe blood flowing through the area of high VQ because there is not much perfusion and lots of ventilation - 98%The blood flowing the through area of low VQ is opposite - 80%What happens when they come back together ? Many more blood cells that are saturated to 80% than there are to 98% The mean would be 89% but that's not what happens Weighted much more to the 80% as many more Roughly 85% saturation
reciprocal apparatus
Two tendinous cords cause united movement of the stifle and hockThe tendons are=Peroneus tertius (front)=Superficial digital flexor (back)Anytime we're going to extend the stifle pulley structure acts on tarsusFlexion of stifle - bend of femur and pull up the hock and metatarsusAllows powerful extensor muscles sited proximally to act upon the distal limbDue to the interaction of muscles and tendons the stifle and the hock joint can only be flexed or extended simultaneously. This mechanism together with the stifle locking mechanism is responsible for the passive stay apparatus.
List the two types of cutaneous pain and relate their speed and quality of effect to the type of endings and axons which mediate them
Two types of pain - fast and slowA fibres = fast conduction, myelinated, well localised sharp pain tend to be larger in diameterC fibres = slow, unmyelinated, dull aching pain, not well localised
hearing in reptiles
Tympanic membrane level with skin in most species (Not snakes, chameleon)1 middle ear bone : stapes (columella) that connects the tympanic membrane to inner earVibrations : air or ground = tympanic membraneà = stapes(columella) = perilymphatic fluid (inner ear)
phagocytosis
Types of white blood cells that are attracted to damaged areas: - Neutrophils - MonocytesThey are said to be phagocytic : they remove bacteria and debris by engulfing or swallowing them
UMNs vs LMNs
UMNs are the manages and may be considered as the 'central motor neurones' due to their locationLMNs are the workers and may be considered as the 'peripheral motor neurones'
Cannot get oxygen to the lungs causing hypoxia
URT obstruction Depends on severity as to whether the oxygen is reduced or can't get to lungsPneumothorax Air has reached the lungs but escapes between the space between the lung and chest wallTracheal collapse
corneal ulcers
Ulcer - discontinuity or break in bodily membraneCorneal ulcer - break in continuity of corneal epithelium with exposure of underlying stromaCausesLid lesionsEyelash lesions eg ectopic ciliumTrauma - lacerations, abrasions, foreign bodyDystrophies/degenerationsInfectionsKeratoconjunctivitis sicca (KCS)Decemen's membrane can bulge up which is extremely serious there are many different types of ulcers
ultrasound of the lungs
Ultrasound cannot penetrate gasNothing in between pleura and lung surface unless there is effusioncan identify lung space, pleura and pleural spaceInflammation of pleura will appear roughened
fate shunt 1 : ductus venosus
Umbilical cord is ligated as placenta detaches There is no blood in umbilical vein therefore the ductus venosus sphincter constricts The blood is diverted through the liver Remnant = ligamentum venosumNo ventilation, equals no clearanceChanges in prostaglandin levels due to breathing - vasoconstrictor levels high (noradrenaline) which facilitates constriction of shunts
summary of journey of vagus up to abdomen
Vagus gone from brain out through jugular foramenIn the neck it has joined our vagosympathetic trunkCarried on through trunk sympathetic system disappearedVagus carries on into the thorax where the laryngeal nerve leaves to the larynxVagus goes through oesophageal hiatus from the thorax to the diagram into abdomen
polymerase enzymes
Viral replications - needs to exploit normal cell processesThey are enzymes that replicate viral genetic material to produce mRNA (protein) and genomic nucleic acidProvided by cellProvided by virusVirus supplies polymerase if not provided by cell
how are positive sense ssRNA viruses produced?
Virus RNA can act directly as mRNA- so genome is directly infectious.RNA translated to produce a single polyprotein.Protein cleaved by viral proteases.Genome replicated by viral polymerase via negative sense strand template.e.g. picornaviruses- foot and mouth virus
How are negative sense ssRNA viruses produced?
Virus RNA cannot act directly as mRNA.Virions contain (and genome encodes for) RNA dependent RNA polymeraseGenerates +ve sense mRNAGenome also replicated by viral RNA polymerase, via +ve sense intermediateTypically replicate in the cytoplasm (there are exceptions)E.g. orthomyxovirus- influenza A has segmented genome with 8 segments which encode different proteins
use of stains on bacteria
Visualisation of microorganisms requires stains as they are translucent.Stains can allow separation into specific groups for diagnostic purposes (image 1 of infected urine sample)A counter stain is a second stain used to contrast parts not retaining the first stain (images 3+4).Some capsules block stains and lead to a halo effect (image 2)
Energy supply diagram
We work on ATP. Pyruvate and lactate which goes through adaptive phosphorylation generating ATPAs soon as there is not enough oxygen to generate it Not enough energy made and is relatively inefficient and generates lactate
6 yr old labrador
We're not worried about oxygenation in the LabradorThe pH is a little lowCarbon dioxide most deviated from normalIs it acute or chronic? We're looking at the magnitude of change The carbon dioxide has gone up by 30 We can look down the table and see this is a acute problem
Rabies virus - nucleic acid?- how spreadincubation periodwhat type of neurological infection do they cause?
What nucleic acid type are Rabies viruses?Single stranded RNA genome of negative polarity encased in a ribonucleoprotein complexHow are they spread?Replication occurs in the cytoplasmNewly synthesize nucleocapsids acquire envelopes from the plasma membrane as virions bud from the cellIncubation period time between infection and signs of neurological involvement is between 14-90 daysWhat type of neurological infection do they cause?Encephalitis
pharmacokinetics
What the body does to the drug or movement of drugs within the bodyPlasma concentration of particular drug Want to be in level of effectiveness but not toxic
pharmacodynamics
What the drug does to the bodyThe action of the drug:Almost always targets protein eg enzyme or ion channelwhat is the response? Might be to reduce inflammationThe response will have a dose element to it - smaller dose smaller response
limbus
Where cornea, sclera and bulbar conjunctiva mergeSource of stem cells for the corneaTenon's capsule = connective tissue sheath that connects bulbar conjunctiva to underlying sclera. Binds everything togetherEpisclera = dense, highly vascular fibrous layer, binds Tenon's capsule to scleraThe cornea is slightly larger horizontal than verticalThickness is 0.5-0.8mm
gular flutter in birds
Where the base of the beak attaches to the neck : gular skinFeatherless areaUsed as a flap or a pouchResults in the heat loss from the mucous membrane lining the throat - flutterCan account for 35% heat loss
alveolar wall
Which layers does oxygen diffuse through to reach the lung capillaries? The walls of the alveoli share a membrane with the capillaries That is how oxygen and carbon dioxide diffuse Oxygen diffuses across the respiratory membrane from the alveoli into the blood Therefore carbon dioxide can diffuse across the respiratory membrane from the blood into the alveoliWhich cells produce surfactant? Type II alveolar cells They are also called pneumocytes This substance lowers surface tension which keeps the alveoli from collapsing after exhalation makes breathing easier
what causes airway inflammation
With prolonged exposure to irritants we get narrowed airways with increased smooth muscle constriction and increased resistance
what happens when acid load is being added to the body
Within the blood it combines with carbonate making carbon dioxide which stimulates the chemoreceptors to increase respiration and carbon dioxide is breathed out
myocardium depolarises
Within the ventricles tends to depolarise from endocardium to epicardium Inside out Happens initially at the apex of the heartResultant dipole points in direction of apex of the heartGives a R wave in ECG
mast cells
Within tissue, role in inflammationResponse to allergens - release histamine
how do viruses hijack host cell machinery to form viral replication factories to enhance viral propagation?
[specialised membranous compartments]- increase local concentration of host and oral factors required- protected environment shielding viral RNA and proteins from degradative environment- coordinates different processes of the viral lifecycle
What do capillary endothelial cells provide?
a barrier of entry of materials to the brain/CNS from blood - also known as BBBprevents cells, toxins and pathogens from entering the brain regulates transport of molecules into and out of the CNS
what happens to hypoxic tissues (from a lack of oxygen)
a carbohydrate (2,3 - diphosphoglycerate) is released = that facilitates release of oxygen from erythrocytes
antiviral immunity
a combination of innate and adaptive immune response mechanisms that works to eliminate viral infection
partial agonist
a drug that binds to a receptor and causes a response that is less than that caused by a full agonistin between full agonist and antagonist= equally partial antagonist in the presence of agonist
define fear and anxiety
a feeling of apprehension in response to an object or circumstance with respect to their proximity or presenceapprehensive anticipation of future danger or misfortune accompanied by a feeling of dysphoriaAnxiety can provide protection:Freezing or immobilityEscape or avoidanceAggressive defenceSubmission or appeasement
explain the concept of a spinal segment
a portion of the spinal cord that gives rise to a pair of spinal nerves, where each is attached to the spinal cord at the dorsal and ventral rootsThere are 31 segments due to the 31 pairs of nerves exiting the spinal cord through the intervertebral foramen
T cell receptor
a protein complex that transmits information from outside the cell to the insideBinds with MHC 1 or MHC 2 (major histocompatibility complex) receptors on other cells
define emotion
a strong or instinctive feeling related to ones circumstances, mood or relationships with others
antigen
a substance that when introduced into the body stimulates the prodcution of an antigen toxins, bacteria, foreign blood cells and the cells of transplanted organs
what are CAMP tests used for?
a test to identify group B β-hemolytic streptococci (Streptococcus agalactiae) based on their formation of a substance (CAMP factor) that enlarges the area of haemolysis formed by the β-haemolysing elaborated from Staphylococcus aureusWhich streptococci is used to identify? Haemolytic
Describe the cardiac events occurring at the sections of the venous pulse:
a wave- due to active atrial contraction leading to backwards blood flow into neck veinsc wave- due to impact of the carotid artery adjacent to the jugular vein and backwards transmission of a positive wave in the right atrium produced by the right ventricular systole and the bulging of the tricuspid valve into the right atrium.x descent- due to continued atrial relaxation.v wave- due to passive atrial filling (venous filling).y descent- due to opening of tricuspid valve and subsequent rapid inflow of blood from right atrium into the right ventricle leading to a sudden fall in right atrial pressure.
ACTH function
acts upon adrenal cortex after it has entered the blood and causes release of corticosteroid eg cortisolreferred to as an axis - all of these glands are connected in function
what are the advantages/disadvantages of synaptic transmission?
advantagesdoes not involve change in chemical concentrationschemical messenger across short synaptic cleftno dilution in general circulationsystem reacts quicklydisadvantagesspecificityhardwiring is expensivepossibly vulnerable
animals experiencing pulmonary disease
alpacas, cattle, horses, Bos taurus cattle,Horses and humans have intermediate effects. European breads of cattle, pigs and black headed turkeys are most sensitivesheep, goats, rabbits, guinea pigs dogs, cats and South American camelids are resistant
effect of noradrenaline on a1-a2 and b1-b3
alpha 1Blood vessels Constriction Agonist: Phenylephine Antagonist: Prazosin, phentolamine alpha 2 Blood vessels Constriction/ relaxation Pre-synaptic Inhibition of NA release Agonist: clonidine Antagonist: Yohimbine, phentolamine beta 1 HEART Increased heart rate Increased contractility Agonist: Dobutamine, Isoproterenol Antagonist: Atenolol, propanolol beta 2 Blood vessels Relaxation Airways Relaxation Agonist: Salbutamol, Isoproterenol Antagonist: Propanolol beta 3Metabolic effects
Neurotransmitters examples principles
amino acids (aspirate, glutamate, GABA), acetylcholine, monoamines, neuropeptidePackaged in to vesiclesPresynaptic membrane depolarises due to action potentialVoltage dependent channels openingAllows calcium in which triggers fusion of vesicles in presynaptic sideWhich leads to neurotransmitter releaseBinding at post and pre synaptic sidesDeactivation
pneumothorax
an accumulation of air in the pleural space and is a frequent cause of dyspnoea in cats and dogs. Causes an increase in intrathoracic pressure and collapse of the lungscausesblunt trauma, penetration wounds, infections, ruptured lung abscess
Ectotherm
an animal that is dependent on external sources of body heat
Endotherm
an animal that is dependent on or capable of the internal generation of heat
what are adherent junctions?
anchoring - cells must bind to each other and to connective tissue to assure tissue cohesion
beta blockers
antagonists to B1 receptor and cAMPThey try to slow the process and try and block neuroreceptors or adrenoreceptorsPropranolol / esmolol
how does antibiotic use lead to increased antibiotic resistance?
antibiotics are an environmental stressselection pressure get rid of all bacteria with low level of resistanceIf the remaining bacteria are not eliminated by immune system they will continue to grow and the next generation is highly resistant
recurrent (or caudal) laryngeal nerve (XI)
ascends the neck after leaving the vagusinnervation of all laryngeal muscles except - cricothyroideus
left atrium
beginningNot on the left it is dorsal and caudalUnderneath the tracheal birfurcationPulmonary veins enter into the left atrium in groups of 2 or 3 sites
Temporomandibular joint
between condylar process of mandible and madibular fossa of temporal bone
how does benzodiazepines work
bind to a regulatory site on the receptor which is distinct from the GABA binding siteIncreases the want for GABA for the receptor by acting allosterically
Somite
blocks of mesoderm located on either side of neural tube in developing embryo
spectral doppler
blood flow can be assessed using different techniques = pulsed wave which records velocity from a single location= continous wave records velocity along a specific line= colour flow doppler records velocity in a specific areaflow is proportional to pressure difference
invasive measurement of measuring the arterial blood pressure
blood into an artery (dorsal metatarsal artery), tubing filled with saline going to transducer measuring the pressure in the dogs artery
what does oxygenation of the arterial blood in the tissues reflect
blood pressure, heart function (contractility and heart rate), lung function and breathing
If D.immitis infection in cats predominantly presents as lung diseasewhat other diagnostic tests may we need to do?
bronchoalveolar lavage (BAL) is a valuable diagnostic tool for the evaluation of cats with lower respiratory tract disease
describe how a limb bud forms
bud grows cells differentiate cartilaginous structures appear proximal structures develop firststarts with proliferation of skeletal precursors from the lateral plate and muscle precursors from somitescells accumulate under ectoderm which creates a bulge = limb budthickening of the ectoderm at tip of limb bud is controlled by apical ectodermal ridge (AER)the distal part of mesenchyme extends the limb bud by proliferation under control of AER - progress zone
caudal colliculus
builders bumAuditory information coordinates head/ear/neck muscles to orientate the animal's head towards sound sourceResponsible for coordination
what is the blood pressure monitored by
by baroreceptors and chemoreceptors located in carotid sinus and aortic arch and the information integrated in the medulla oblongataBaroreceptors sensitive to stretchChemoreceptors sensitive to pO2 and pCO2 changes
how can arterial pressure be measured?
by sphygmomanometer (non invasive) in dogs, cats, pigs and horses and invasive methods (direct) with fluid filled catheter
panniculus response
can be stimulated by a gentle pinch to the skin resulting in a twitch of the cutaneous trunci muscleIn the dog this is demonstrable from the level of the scapula to the pelvi
pulmonary hypotension summary
can result in the development of pulmonary oedema as fluid gets pushed from those capillaries that are under pressure into the alveoli. The pulmonary hypertension can back up causing thickening of right ventricular myocardium - right ventricular hypertrophy and then if we begin to get dilation and poor contractility causes right sided heart failure. Cerebral oedema due to vasodilation in response to hypoxia. Hypoxia also triggers the kidney to release EPO increases RBC numbers. Can also see prevention of maturation of the foetal to adult circulation
protein buffers when there is an increase in pH - becomes more alkali
carboxyl group - dissociate and act as a weak acid releasing H+, becomes carboxylate ion -COO eg histidine and cysteine amino acids are important H+ donors
Identify and describe the bones and joints in the distal limb
carpal - metacarpal joint, metacarpo-phalangeal joint (fetlock), proximal interphalangeal joint (pastern) and distal interphalangeal (coffin)
The vagus nerve
carries all the parasympathetic supply to thorax and abdomen10 the cranial nerve exists as a series of rootlets from lateral surface of medulla oblongata Exit - exits skull through jugular foramen with cranial nerves XI an IXAlso picks up fibres from CN XI which are destined to be in recurrent laryngeal nervesensory supplyear skin and larynxGut distention, pain, blood pressureTaste (caudal tongue/cranial larynx)motor supply Parasympathetic organs and glandsMotor to larynx and pharynx
function of the peripheral nervous system?
carry impulses or messages to and from the Central Nervous SystemNerves outside of skull and spinal protectionIncludes all cranial nerves except optic nerves
feline heartworm
causes acute lung injury in cats
drug targets for antibiotics?
cell wall synthesis, cell membrane function, nucleic acid synthesis, protein synthesis
hindlimb adaptations in horses?
coiled spring shape providing forward impulsion of the horse,Stay apparatusIt is a stifle locking mechanismReciprocal apparatusSuspensory apparatusThe animal needs to be ready to run works with reciprocal apparatusRigidity of leg without using muscular forcemedial patella ligament allows patella to become locked over the trochlear ridgestifle becomes locked in extension - holding hock as well
fetal lungs
collapsed, unnecessary, have high resistance pulmonary artery won't be pumping blood to it due to it being high resistance
what are gap junctions?what is controlled by gap junctions?what are the physical properties of gap junctions?what do gap junctions allow?what are gap junctions essential in?
communicating - cells must communicate with each otherwhat is controlled by gap junctions?cells from the body must communicate efficiently which is controlled by gap junctions - adjacent cells communicatedwhat are the physical properties of gap junctions?aqueous channels allowing small molecules to pass between two adjacent cellswhat do gap junctions allow?movement of ions and movement of metabolites and intracellular signlaling molecules such as cAMPwhat are gap junctions essential in?embryonic development
arterioles
composed of smooth muscle cells, these cells can contract diminishing the radius of arteriolesDecrease in the radius results in a corresponding increase in blood pressureThe contraction of the arterioles regulates the blood pressure and they provide the resistance to blood flow
two main types of asexual spore:
conidia formed on conidiophores and sporangiospores formed on sporangiophores in dermatophytes (skin infecting fungi) you get macroconidia and macroconidia
what is the epitenon?
connective tissue sheath which defines the tendon unit
submucosa
contains numerous mixed seromucinous glands which decrease in number in the lower trachea,
Apoptosis
controlled death of cells
function of central nervous system?
controls the function of the body and mindSpinal cord Evolution causes limbs to become detached at the skull Muscles can move during evolution but the nerve connections remain the same - some can take odd routes to maintain this Adaptation for running over land/endurance is the lack of movement in the head and neck in order to conserve energy
cortisol
corticosteroid hormone that is produced by adrenal cortex in the adrenal glandIt increases blood pressure, blood sugar levels and has an immunosuppressive action
Define the main divisions of the peripheral nervous system?
cranial nervesspinal nervesautonomics
what is the main supply to distal hindlimb?
cranial tibial artery which continues as the dorsal metatarsal artery
what are the characteristics of the process of somitogenesis (how is it formed but not process)?
cranio-caudallyregular and coordinatedsynchronous with neuralationappear at same time
closes the glottis
cricoarytenoideus lateralis
what is the critical point to sleepfull ness/wakefullness
critical point is switch in this mechanism of the level of activity of the inhibitory neurones in the locus ceruleus and dorsal raphe nucleus
horner's syndrome
describes a dysfunction of the sympathetic nervous supply to the eye.Ptosis, Miosis (excessive constriction), EnophthalmosIpsilateral excessive sweatingAngle of eyelidIpsilateral dry nose is an indicator for Horner's Syndrome in a cow
pressures in anatomy and thorax transpulmonary
difference between alveolar pressure and intrapleural pressure
what microscopic examination can be completed with blood smears
differential leukocyte counts, erythrocyte and leukocyte morphology, presence of any abnormal cells and parasites, platelet counts, send with EDTA sample for blood analysis, cheap
location and function of SDFT?
distal end of P1 it splits and inserts on P2 flexes proximal and middle phalangeal joints and stabilises joints
hemiwalking
dog is hopped sideways on both fore - and hindlimbsThis test is more difficult for the dog and may demonstrate more clearly subtle changes on single limb hopping
what is acidosis caused by?
due to ATP hydrolysis which causes post race panting
dura meterpia meterarachnoid meter
dura meterIntracranially adherent to periosteum of skullTough layer mainly made of dense connective tissue seen around spinal cordpia meterthin layer adherent to underlying brain / spinal cord = blends with arachnoid arachnoid meter Fine layer pressed up against dura mater with fine whispy filaments which extend to and blend with pia mater
acute respiratory acidosis
eg an opioid user and horse under anaesthesiaconsequence of both these scenarios carbon dioxide increases and pH has dropped obesity hypoventilation syndrome: obese individuals they fail to breathe deeply enough and the overriding result is they end up retaining carbon dioxideDisplaces oxygen and are chronically hypoxemic - low o2 and high co2
crura/crus
elongated body structure especially one that occurs in the body as a pair
describe the mechanism of formation of synovial joints in a developing limb
endochondral ossification gives rises to the bones and joints of limbeach limb bud continues to grow and elongateareas of mesenchyme within the bud begin to differentiate into hyaline cartilage that will form models for each of the future bonessynovial joints will form between adjacent cartilage models in the joint interzonecells at centre of joint interzone undergo apoptosis to form joint cavityhyaline cartilage is retained
where is it found and what are the properties of elastic cartilage
epiglottis, larynx, external ears, external auditory canalsHigher proportion of elastic fibres within the ECM
role of stress is as behavioural sensitisation: what is sensitisation?
example of non-associative learning in which the progressive amplification of a response follows repeated administrations of a stimulus
what are all afferent fibres to the cerebellar cortex
excitatory
dipoles
exist within the myocardiumIt is a negative and positive charge separated by a short distanceCurrent flows between the poles as consequence of ion movement
immunological memory
exposure of an immunologically primed animal to the same antigen which leads to the activation of memory cells, which were established during the primary immune response. An enhanced immune response is the outcome
Osteochondritis :
extension of lesions to the articular surface causing inflammation of the joint - can be caused by small fissures/fractures
fast fibres vs slow fibres
fastform monosynaptic connections which go to straight down to alpha motor neurones which connect to rest of muscle fibresProduce impulses proportional to rate of change of length of intrafusal muscle fibresslow polysynaptic responsesProduce impulses proportional to the tension within the intrafusal muscle fibres responding to change in length
which peripheral nerve is tested by the patellar reflex
femoral
Identify the main synovial structures of the distal limb
fetlock pastern and coffin jointTo the rear of the coffin joint there is the synovial membrane of the coffin joint and tendon sheath
spino(cervico)thalamic tract
first order neurone synapses in dorsal horn of spinal cord which synapse with second order neuronesthey decussate to go up spinothalamic track up the spinal cordthird order neurones arise from contralateral thalamus which then ascends to cortex
what is lymph
fluid from the blood moves into spaces surrounding cells of the tissue - interstitial fluidIt is similar to plasmaContains more lymphocytes than are present in bloodIt contains pathogens, cell products and cell debris too from the body
Three vector model of behaviour
for instance bird songInput vector - bird singingState vector - is it a male singing or a female if it is a female it will switch to approach or attackOutput vector - the attack or approach
what do the endocardial cushions form and what is the cardiac anomaly that results from endocardial cushion developmental failure
form the mitral and tricuspid valves. These are the valves that separate the atria (top collecting chambers) from the ventricles (bottom pumping chambers).ostium primum defect. The failure of the endocardial cushions to fuse results in an abnormally low position of the AV valves and an abnormally high position of the aortic valve.
what comes before formation of neural tube?
formation of notochordwhat is the formation of notochord?Prenotochordal cells invaginate and move craniallyIntercalate in endoderm = notochordal plateCells detach = notochord
Erythropoiesis
formation of red blood cells from stem cellsin the embryo: yolk sac, liver (lesser extent the spleen), shift to bone marrow in later foetal stageAfter puberty : primarily in marrow of membranous bones
what is somitogenisis
formation of somites-
development of the lens
forms as out budding of neuroectoderm making lens placode and then lens vesicle formsPosterior cells elongated forming primary lens fibres
where is it found and what are the properties of hyaline cartilagemost common type ,
found in most bone - forming sites, joint surfaces, tracheal rings, larynx and nose
sacral vertebrae characteristics?
fused together to form sacrum / sacral boneDorsal spinous processesHasn't got transverse processes as that's where it fuses with pelvisBetween each vertebrae there are holes - intervertebral foramen - hole to allow the nerves to come out
ataxia
general inability to move in a coordinated way
what are endocrine (ductless) glands?
glands that lack a duct system - no connections to external or internal surfacesproduce hormonesnear blood vesselshigh diversity in morphology
how can a vet help with husbandry
good welfare biosecurity and breeding, medical prevention - vaccines, no prophylactic treatment and medical treatment - drugs and therapy
why has cattle lungworm increased?
he treatment is anthelmintic treatment eg ivermectinThere is also a (Huskvac) this irradiated L£ larvae and was a protective response against L4 = response protects against development of adults which produce eggsIncreased reliance of anthelmintics instead of vaccination comprises the build up of immunological responses - even in vaccinated animalsSurvival of L3 on pasture may have improved due to climate change - causes it to be warmer
what controls heart rate and rhthym and force of contraction
heart rate and rhythmPost ganglionic fibres go to the SA Node and the AV node - in the walls of the heartpositive chronotropic effectforce of contraction Post ganglionic fibres also go to myocardiumThis controls the force of contractionPositive inotropic effect
guttural pouch
horsePharyngeal opening of the auditory tube (arrow)Connecting tunnel between nasopharynx and middle earSpace between base of skull, atlas, pharynx and oesophagusDivided into 2 cavities by the stylohyoid boneFunction - not sure maybe to do with cooling of bloodimportanceFungal disease Vascular and neurological conditionBacterial disease S equi var equiEntry into the pouch maybe required Viborg's triangle only useful if distended Can be achieved with an endoscope or without
paratenic host
host used to host the parasite without any further development eg rodent, cat or dog lungworms
Describe the structure and function of the wings of the bird
humerus, ulna, radius, manus (semi-fused 3 fingered hand) consists of the carpal bones the carpometacarpus and digitsHumerus has large pneumatic foramenRadius and ulna are bowed apart to aid in forces of flight the ulna has primary flight feathers attached
Why does oedema occur?
if we have increased (outward) filtration pressure caused by an increased arterial pressure and venous pressure. Which could be due to obstruction of vessels locally and generalised increase in venous pressureA decreased - inward - absorption pressure will also cause oedema the only time we see this is with a fall in plasma COP, protein loss, reduced protein synthesis
contractility?
impacted by the sympathetic nervous system, the force by which the ventricles contract - determines how much blood is left in the ventricles at the end of systole (ESV)
difference in species in distal limbs?
in horse interosseous is entirely tendinous but in dog and cat it is musculardifferent ray patterns as abaxial digits lose contact with the ground in faster animals that are adapted for speed reducing muscle massdifferent numbers of metacarpal bonesinterossei III and IV fused in cow - separate and insert on corresponding digitsin cows there is also a dorsal common digital artery in forelimb and dorsal metatarsal arteries in hindlimbstump of axial palmar artery bleeds profusely and must be ligated
Compare and contrast the anatomy of the distal limb in different domestic species
in horse interosseous is entirely tendinous but in dog and cat it is muscular different ray patterns as abaxial digits lose contact with the ground in faster animals that are adapted for speed reducing muscle mass different numbers of metacarpal bones interossei III and IV fused in cow - sepearate and insert on corresponding digits in cows there is also a dorsal common digital artery in forelimb and dorsal metatarsal arteries in hindlimbstump of axial palmar artery bleeds profusely and must be ligated
where is the palmar digital nerve block and where does it desensitise?
in pastern regionneurovascular bundles can be palpated abaxial to flexor tendons desensitises hoof structures other than dorsal coronary band
Laryngeal hemiplegia
inadequate gas exchange due to collapse of the larynx -roaringTreated surgicallyHence importance of pre-sale endoscopic examinationsCamel are nose breather - have specialized inflatable diverticulum of the soft palate
glaucoma
increased intraocular pressure which damages the optic nerve = cloudy painful red eyesIntraocular pressure depends on volume of aqueous present on ocular rigidityConstant production and drainage of aqueous by ciliary bodyGlaucoma = raised intraocular pressure Blinding - damage to optic nerve heard disrupting microcirculation and axoplasmic flow within retinal ganglion cell axons Pain Treatment is challenging
What is Eisenmenger's syndrome?
increased right ventricular pressures and therefore right-to-left shunting during systole may occur;Right-to-left shunting allows deoxygenated blood to enter the systemic circulation, resulting in arterial hypoxaemia and cyanosis.A hole between the chambers in the heart
adenosine what it does
increases potassium efflux and decreases calcium influxnegative chronotropic effect and reduced AV node propagation short acting treatment for SVT hyperpolarises the action potential - negative chronotropic effect slowing the heart rate
starling effect
increasing stretching of heart muscle leads to increased contraction
pKa
independent of concentration and is the tendency to dissociate into H+ and A-Tells us how much a substance is dissociating in a solutionpKa - the pH at which 50% of the molecules are ionised - ie there are equal numbers of ionised and non-ionised
what happens in the response to haemorrhage in adrenal glands
indirect effectssympathetic stimulation of adrenal gland causes release of adrenaline (epinephrine) in bloodionotropic and chronotropic effects
dacryocystitis
infection of the tear ducts, often clinically important in rabbits which suffer with teeth issues which can cause blockages and therefore infections. It can often cause chronic ocular discharge.
what are lipid rafts?
interaction between lipids generate rafts that are more ordered and tightly packed than the bilayer and float freely in membrane and very important for signalling
what factors may increase the possibility of d.immitis in cats becoming an important pathogen in the future in UK?
introduction of exotic infection with improted rescue pets or with pet returning from endemic areas abroadclimate change / global warming = increase in vector population and adult mosquitoes are able to live longer
chemoreceptors
involved in homeostasis they control the ventilation rate to change acidity by increasing or decreasing the removal of carbon dioxide they are contained in the respiratory centres and detect pH levels in the blood and send signals.present in brainstem, cerebellum, hypothalamus and midbrain - medulla
what is the components of the lens?
is 35% proteins and 65% water - soluble proteins - cystallins and insoluble proteins - albuminoids
macconkey agar
is a selective and differentiating agar that only grows gram-negative bacterial species; it can further differentiate the gram-negative organisms based on their lactose metabolism.It contains bile salts (to inhibit most Gram-positive bacteria), crystal violet dye (which also inhibits certain Gram-positive bacteria), and neutral red dye (which turns pink if the microbes are fermenting lactose).Salmonella sp.E.coliBoth will grow well
micropthalmos definition - Globe size (normal/enlarged/reduced)Globe position (normal/protruding/sunken)Appearance of eye itself (normal/abnormal)
is a severe developmental disorder of the eye in which one or both eyes are abnormally small and have anatomic malformations.abnormalsunkenAbnormal
Apical ectodermal ridge
is a structure that forms from the ectodermal cells at the distal end of each limb bud and acts as a major signalling centre to ensure proper development of a limb
what is stereotypic behaviour?
is repetitive behaviour induced by frustration, repeated attempts to cope and/or CNS dysfunctionthe criteria to define are:=Repetitive=Invariant=No function
enophthalmos definition - Globe size (normal/enlarged/reduced)Globe position (normal/protruding/sunken)Appearance of eye itself (normal/abnormal)
is the posterior displacement of the eyeball within the orbit due to changes in the volume of the orbit (bone) relative to its contents (the eyeball and orbital fat), or loss of function of the orbitalis muscle.NormalsunkenNormal
why is cell signalling important?
it allows for coordination of a wide variety of processes including:movementmetabolism - differentiated cell types specialised for metabolic processesgrowth - unrestricted growth would disrupt functional and structural integrity (cancer)developmentimmune response - involved in activation and recruitment of neutrophils for cytokine production which stimulates other cells
why does haemoglobin bind to nitric oxide as well
it is a neurotransmitter that causes dilationPermitting maximal tissue perfusion for supply of oxygen/removal of waste products
retina in reptiles
it is avascular+/- conus papillaris is lizards and some snakes - thin highly vascular tissue which supplies the nutrition to the retinaMore rods in nocturnalFovea centralis gives better vision in lizardsLizards on left and snakes on rightSub spectacular space
benefits of a micro-flora
it is bacteria that lives inside the intestineCommensals do interact with the immune system and allow the development of key cell types and immune tissuesNeonates maternal antibodies protect the neonatal animal from infection by the commensals
what is the corpus callosum
it is the largest commisurebiggest connection between the two hemispheres
alveolar ventilation
key importance and is the amount of fresh gas getting to the alveoli (tidal volume-dead space) x respiratory frequency
neutrophils oxygen independent
killing occurs in sites of poor blood flow or at abscessesLysozyme = hydrolyses glycopeptide coats of many bacteriaCathepsinHydrolytic enzymes
knuckling
knuckling or paw repositioning test is the easiest and often most sensitive test to demonstrate altered proprioception in the digIf a weight bearing/pain free paw is placed with the dorsum on the ground then there should be a rapid return to normal positioning
What is chylothorax
leakage of Chyle into thoracic cavity as thoracic duct has split - not commonOften linked to underlying conditions such as heart disease, blood clots, heart worms or tumours
hydrostatic pressure
left ventricle driving bloodPlasma exerts a pressure against the inner capillary wall and promotes the formation of tissue fluidNet filtration pressure (OUT of vessel) - forces fluid out of vessel
necrosis
lethal cell injury or accidental cell death in organismCAUSED BY Injury, infection, cancer, infarction, toxins, inflammationWHAT HAPPENS DURING NECROSISThey swell because the ability of plasma membrane to control passage of ions/water is disruptedInternal organelles eg mitochondria also swellCell contents leak out leading to inflammation of surrounding tissues - failure of membrane integrity
annular ligaments
local thickenings of fascia which stabilises tendon
clinical findings of oedema
localised or generalisedfluid in skin - pittingfluid within i/s tissue in a body system eg lungsFree fluid in body cavities : pleural fluid - cat - heart failure, ascites - dog - R heart failure, cattle and horses develop 'brisket' oedema in the heart failure
location and function of extensor tendons of digits?
located on dorso lateral aspect and innervated by radial nerve extension of digits
what happens as erythrocytes age?
lose sialic acid residues from the surface (exposing galactose moieties that induce their phagocytosis) which become more fragile and may become swollen due to failure of normal membrane function and may become swollen due to failure of normal membrane function
What does chyle contain and where does it drain?
lymph from the digestive systemContains protein coated lipid droplets called chylomicronsDrains into lymphatic capillaries known as lacteals in small intestineLacteals return chyle to chyle cistern - the origin of thoracic duct
RBC morphologyCell sizeMHC HIGHNORMALMHC LOW
macrocyticnormocyticmicrocytic
location and function of common digital extensor - forelimb
main extensor of digitstendon of insertion split to number of functional digits in species inserts on extensor process of P3
facultative parasite
may survive in absence of host eg opportunistic
what happens in the response to haemorrhage in medulla oblongata- autonomic effect of heart
medulla oblongata = cardiovascular centreneural stimulation of the heart= direct effects to the heart = autonomic
brain stemfunction and fibres
medulla oblongata and ponsfunction : Location of important regulatory centres Respiratory Blood pressure Heart rateSeveral cranial nerves emerge and have nuclei here Balance Hearing Swallowing Masticatory musculature salivationfibres pass through efferent and afferent
innervation of the horn
most arise from trigeminal nerve - the 5th cranial nerve of the headCornual nerve - all animals: Located halfway between lateral canthus and horn base - along ridge of frontal boneCornual branch of infratrochlear nerve: Located between medial canthus and medial horn base - 90% of animalsFrontal nerve (15% of animals)Frontal sinus nerve (5% of animals) - within sinusCutaneous branches from 1st and 2nd cervical vertebrae - caudally
basis of differentiation of fungi
moulds and yeastsSize appearanceColourSurface elevation depressionsOther patternsmouldsExamination of spore structuresFrom culture or clinical sampleFeatures of vegetative hyphaePresence absence of septaHyaline (colourless) or dematiaceous (pigmented)Hyphal structures (spiral, racket shapes)
what is the natural route of flow of CSF?
moves into the third ventricle and then into fourth ventricle then either down spinal cord canal or passes out going out lateral apertures
topography of the trachea birds
much longer trachea than mammalian (2.7x times longer, 1.29x wider)Increased tracheal dead space:Compensate for this - slower and deeper breathing rate compared to mammals - 1/3 of the rate
What are the three types of neurones
multipolar Typical neurone, single axon and multiple dendritesUsually motor neurons and interneuronesA collection of nerve cell bodies inside the CNS is called a nuclei and in the PNS it is termed a ganglionbipolarUncommon, single dendrite and axonFound in sensory pathwaysunipolar Typical in sensory neuronsSingle process leaves cell body and divides into two, acting as a dendrite and an axon
what do somites contain and what does this allow?
multipotent cellsthese diffeerntiate to become different sorts of tissuewhere the multipotent cells are found in the somite determines its fate
which receptor organ is used to initiate a myotatic reflex
muscle spindle
what does mesoderm form?
muscles, organs of circulatory, respiratory, skeletal, reproductive, excretory systems
which peripheral nerve is tested by the biceps reflex
musculocutaneous
R wave in the ECG
myocardium depolariesesresult dipole in direction of the apex of the heart
activation of metabotropic receptors - G protein
name meaning is they require steps that the cell expend metabolic energyreceptor located close to G proteinneurotransmitter binds with receptor the receptor activates a g proteinthe g protein activates an enzyme that stimulates the production of a chemical called a second messenger (neurotransmitter is first messenger)second messenger molecules travel through cytoplasm causing nearby ion channels to open by attaching to themtakes longer but last longer
skeletal muscle?
narrow spindle shaped fibresseveral nuclei within each cell at peripherydistinct transverse striations within cytoplasm
immediate emergency treatments required for a septic foal
nasal oxygenkeep warmrehydration/fluid therapykeep in sternal recumbence
explain the origins of the neural tube and how it differentiates
neural tube expands to form thick lateral walls with thin bands of tissue at the top and bottom forming roof and floor platesindentation of the neural canal delineates dorsal and ventral columns within the intermediate zonealar plate - sensory neuronsbasal plate motor neurons - somatic or autonomicboth these plates give rise to dorsal and ventral horns of spinal cord
affect of ACh on nicotinic and muscarinic receptors
nicotinic nAChR Muscle Ganglion CNS Agonist: nicotine Muscarinic mAChR M1 Neural M2 HEART Decrease heart rate Decreases contractility Agonist: muscarine Antagonist: atropineM3 Glandular/s mooth muscle
capillaries
no collagen or elastin, relatively low blood pressure because:= Capillaries are fragile so high pressure would tear= Very permeable high pressure would force fluid out
what are tight junctions?
occluding - cells are invovled in the control of what enters the body
C3b main role
opsonisation and phagocytosisCan bind to microbial surface and tag it for phagocytosisComplement receptors expressed on phagocytes
what are the functions of the midbrain/mesencephalon?
optic reflexesregulation of motor functionseye movementarousal
what is simple couboidal and columnar epithelium associated with?
passive transport across cytoplasmsimple cuboidal : thyroid, lung, kidney, ovary, ducts and secretory of many glandssimple columnar : intestine, female reproductive tract and many exocrine glands
persistent (chronic) infection
pathogen is detectable for the lifetime of host
What are the two main factors that determine end-diastolic volume?
preload and stroke volume Preload dependent on venous return of blood, central venous pressurePreload controlled by the filling of the heart and the venous return
what is virus entry dependent on?
presence of appropriate cellular surface receptors
Osteochondritis dissecans (OCD):
presence of dissecting osteochondral flap - fragments can fall off
what is the rate of airflow proportional to
pressure difference
defence of lungs = prevention of entry
prevent entryThe head position encourages drainage of the respiratory tract = head lowers to eatThe nares : size, position, distribution of hairs withinNasal cavity : narrow passages, turbulence, particle deposition
three categories of buffers
proteins, phosphate and carbonic acid-hydrogen carbonatecan also be grouped dependent on location in the body intracellular buffers, proteins and phosphates or extracellular buffers - bicarbonate and haemoglobin
Identify the location of the synovial structures and the main sites for synoviocentesis in the distal limb =
proximal axial base or distal four different spots for removal
right heart
pumps deoxygenated blood to the lungs
left heart
pumps oxygenated blood to the rest of the body
Why can rRNA be sequenced to group pathogens?
rRNA has conserved regions which are species specific and allows bacteria to be grouped into species. They can then be grouped further by comparing non-conserved regions.
which peripheral nerve is tested by the triceps reflex
radial
what are the four physical processes of heat exchange
radiation, convection, conduction and evaporationConduction - transfer of heat by two objects that are in direct contact with one anotherConvection - transfer of heat to the air surrounding the skinRadiation - transfer of heat via infrared waves which occurs between any two objects when their temperatures differEvaporation - transfer of heat by the evaporation of water
mast cells
rapidly release their granules (contians histamine, proteoglycans, serine protease) and inflammatory mediators into the interstitum and can react quickly
properties of non specific nuclei
receive less functionally distinct afferent inputconnect with wider area of cortex, including associative and limbic regions
function of the enteric nervous system?
regulates digestive tract motility, secretion, and blood flow - controls the gutNetwork of two layers of cells within the walls of the gut; own pacemakers & intrinsic activityInfluenced but not controlled by autonomic system - operates automatically and autonomouslyInner and outer network of ENS nerves in GIT lumen to set intrinsic rhythms
dubventricular diastole
relaxation of ventriclesResults in ventricular fillingSemi-lunar valves closing
What is acute inflammation
repair of the damage and removal of infection that is normal response to most forms of injury/infection that takes a matter of daysexample infection by microorganims, hypersensitivity, burns and irritants
afterload
resistance to ventricular ejection, pressure in whole system rejecting ejection
explain the process of endochondral ossification
responsible for majority of skeletal growth during foetal developmentbones initially formed from cartilage and cartilage is then replaced by boneprovides mechanism for growth whilst weight bearingCartilage found in physis that is involved in endochondral ossificationCartilage continually being formedShunted by cartilage cells coming behind themBone formsPrimarily responsible for growth in length
when is the parasympathetic nervous system activated?
responsible for the body's rest and digestion response when the body is relaxed, resting, or feeding. It basically undoes the work of sympathetic division after a stressful situation.
how is perfusion affected by posture
s V/Q less at base of lung — more blood flow than ventilation V/Q higher at apex — more ventilation than blood flow With exercise — V/Q more even throughout lungs Why might a ventilation/perfusion mismatch occur when you are carrying out abdominal surgery on an animal such as a horse? dorsal recumbency may cause lungs to compress and can affect perfusion
visceral pain components?i
s very poorly localisedlittle evidence of somatotropyCan travel in sympathetic fibresLarge overlapping receptor fieldsResponds to stretch, ischaemia, dilation and spasm
which peripheral nerve is tested by the cranial tibial reflex
sciatic
Proprioception
sense of the position and movement of body segments and it relies upon the presence of receptors embedded in skeletal muscle, tendons, joint capsules and ligaments
activation of ionotropic receptors
sensitive to acetylcholine (Ach)Ach binds to alpha subunit and opens the channel for Na+ in and K+ outwhen these channels are open sodium ions enter the cell and depolarise the membrane
positive sense
sequence can code directly for virus protein
what is the inflammatory response and function
series of local cellular and vascular responses which are triggered when the body is injured or invaded by antigenprevent the spread of microorganisms or antigen to other areas, to dispose of any cellular debris and to begin the healing process
function of the thalamus
serves as a relay station for information destined for higher centres - cerebral cortex
epidermis
single layer of growing cells with keratin layer above it
vocal fold
slightly stiffer elastic ligaments and pass between the arytenoid cartilages and the laryngeal floorThey rund caudodorsally with the ligament positioned medially and vocalis muscle laterallyFat surrounds the vocalis muscle - the vocal folds form part of the glottis and secrete mucus = they are used for vocalisation
what are cytokines?
soluble proteins or glycoproteins produced by cells that are important signalling molecules especially in inflammationin the inflammatory response : when damaged cytokines are produced which stimulate resident cells (mast cells) and recruit neutrophils (produce cytokines too)acute phase reactants produced and chemokines are released - they are basically singalling beacons that tell the neutrophils and monocytes wehre the areas of infections are or the areas of inflammation and they migrate along chemokine gradient
four types of pain
somatic painPain experienced from skin, muscle, bone damage/diseasevisceral pain Pain experienced because of organ pain (abdominal or thoracic)neuropathic Pain caused by a lesion or disease of the somatosensory nervous system (in contrast to nociceptive pain)pain windupWind-up is a frequency-dependent increase in the excitability of spinal cord neurones, evoked by electrical stimulation of afferent C-fibres
normal lung appearance
sound does not penetrate normal aerated lungonly visualise smooth, freely gliding surfaceminimal fluid in pleural cavity
what are the functions of virus proteins?
strucutal proteins encode= capsid which protects the nucleic acid= envelope of glycoproteins mediate recognition of host cells and entry non structural proteins= mediate replication of genome accessory proteins = special functions usually restricted cell types
what is the SCN?
suprachiasmatic nucleusPrimary pacemaker entrained to solar time by retinal afferentsMaintains and synchronises tissue-based clocks in major organ systems by a blend of endocrine, autonomic and behaviour cues
where do the sympathetic neurones enter after exciting the spinal cord?where do the sympathetic nerves travel to?
sympathetic trunkwhich runs along parallel to the vertebrae one on either side so there are two sympathetic trunksThe head: via the cranial cervical ganglionThe neck: via the cervicothoracic ganglionThe thorax: via the middle cervical and/or cervicothoracic gangliaThe abdomen: via splanchnic nerves then coeliac, cranial mesenteric or caudal mesenteric gangliaThe pelvis: via a splanchnic nerve then the caudal mesenteric ganglionThen onwards to the target organ via other nerves.
SIRs
systemic response to an array of severe clinical insults
what is pulse pressure equal to
systolic - diastolicDifference between pressures high pulse pressure does not equal high MAP and therefore does not mean good tissue perfusion
what creates a pressure waveform?
systolic ejection of bloodblood vessels accommodate the increase in pressure - have some compliance but when the stretch stops there will be a slight rise in pulse pressure helps to maintain pressure
output vector
the aspects of a response behaviour or motor pattern which are generated by the animal and able to be observed and often specific to a particular species for example birdsong, grooming, resting and locomotor habits
what is atrial diastole?
the atria relax, allowing them to fill with blood again
Mean corpuscular haemoglobin (MCH)
the average amount of haemoglobin per red blood cell that is measured in picogramsDerived from total haemoglobin divided by red blood cell count
protein buffers when there is an decrease in pH - becomes more acidic
the carboxylate ion -COO and the amino group NH2 can act as weak bases and accept H+this forms the carboxyl group - COOH and amino ion -NH3
spine manipulation
the cervical spine in the dog is a high movement region and you should be able to demonstrate a good range of movement in both flexion/extension and laterally.Dogs head all the way to spine
doppler ultrasound
the change in frequency that occurs when sound is reflected by a moving objectThink of it as a trainCloser louderCan apply to blood or myocardium - tissue DopplerAs the object moves towards the frequency of the sound will be higher than an object moving away from us identifies velocity of blood flow (and direction)
tactile placing
the dog is brought up the edge of a table whilst blindfoldedWhen the limbs touch the table they should be accurately placed onto the table
paper slide
the dogs limb is placed on a piece of paper which is then pulled laterallyIf a weight bearing/pain free paw is moved outside the body the limb should be rapidly and accurately retuned to a normal position
Alveolar ventilation (VA)
the exchange of gas between the alveoli and the external environment, and it can be calculated by multiplying the breathing rate with the tidal volume minus dead space, making it less than the minute ventilation.
Why is foetal circulation different
the fetus 'breathes' amniotic fluid as the lungs are not inflated which means the pulmonary artery does carry oxygenfetal blood is oxygen poor - hypoxemicfetus swims in amniotic fluid - stable temperaturefetus is fed parenterally - umbilical cord
intermediate host
the host in which parasite asexual reproduction occurs
definitive (final) host
the host in which parasite sexual reproduction occurs
What is infection?
the invasion and or colonisation by and subsequent multiplication of pathogenic microorganisms (pathogens) in a bodily part of tissue which can produce subsequent tissue injury and progression to overt disease through a variety of cellular or toxic mechanismsCould be direct damage to a tissue for example
Vital capacity (VC)
the maximum volume of air that can be expired after maximum inspiration, making it the total of the inspiratory reserve volume, the tidal volume and the expiratory reserve volume.
what is gastrulation?
the process where by three primary germ layers are established in the embryo forming endoderm, mesoderm and ectoderm
Respiratory rate (f)
the rate at which breathing occurs, usually measured in breaths per minute.
What is packed cell volume (PCV)?
the ratio of the volume occupied by packed red blood cells to the volume of the whole blood
pleura and pleural cavity
the serous membrane around each legpleural sacs formed from two pleural membranes around each legpleural cavitythe narrow space between the parietal and viscera pleura= Contains a small amount of serous fluid spread over pleura surfaceEstablishes adhesion with thoracic wallFacilitates smooth movementLung follows movements of diaphragm and thoracic wallSub-atmospheric pressure
what is epidemiology?
the study of distribution and determinants of health-related states
Minute ventilation (VE)
the total volume of air entering the lungs in inspiration in one minute, the total being breathing rate multiplied by tidal volume.
minute ventilation
the volume of air inspired or expired per minuteTIDAL VOLUME X FREQUENCY OF BREATHING
Dead space (V0)
the volume of air inspired which is not taking part in gas exchange, due to either remaining in the conducting airways or reaching alveoli which are poorly perfused.
Functional residual capacity (FRC)
the volume of air left in the lungs after passive exhalation, making it the total of the expiratory reserve volume and the residual volume.
Residual volume (RV)
the volume of air remaining in the lungs after fully exhaling, after exhausting the expiratory reserve volume as well.
Inspiratory capacity (IC)
the volume of air that can forcibly inspired after a normal, passive inspiration, and it is the total of the tidal volume and the inspiratory reserve volume.
minute volume
the volume of air that enters and leave the lungs each minute (ie tidal volume x respiratory rate)
tidal volume
the volume of air that enters and leaves the lungs with each breath
Vestibular dysfunction understandable
there is a peripheral vestibular apparatus on each side of the head for a reasonperipheral components as primarily excitatory, so that the loss of one side will lead to relative hyperactivity from the other side.Tonic activity from both sides of the head generally keeps us all from falling over constantly.In the normal patient, rotating the head to one side will stimulate the vestibular system on that side. This will lead to a jerk nystagmus with a fast phase to the direction the patient is being turned.
why do erythrocytes not have organelles?
they gain their energy from anaerobic metabolism so don't need mitochondria this avoids consumption of any oxygen they are carrying no nucleus - division stem cells instead this increases the space for haemoglobin and allows bio concave shape all derived from stem cell division
How do therapy drugs work in the CNS?
they have to get the right concentration Eg for antibiotics to be effective they need to reach the right concentration in the CNS Selection on a drug with relevant penetration of CNS can be very important
what are tendon sheaths?
thin walled double layered fluid filled tubes surrounding stretches of tendonsEnclose tendons like tubes protecting them from pressure and reducing frictions
What is the largest lymphatic duct?
thoracic ductfrom the cisterna chyli drains into cranial vena cava takes away everything /lymph from the head travels dorsal from aorta and returns lymph to vena cava
what do somites form?
three different types of connective tissue - dermatome, myotome and sclerotome
total ventilation
tidal volume x respiratory frequencytidal volume increases when animal exercising
haematology why do we do it
to rule out other causes of dyspnoea.Eosinophilia and hyperproteinaemia may be seen in some asthmatic cats.
where is the syrinx located? in birds
tracheal birfurcation Both the lateral and medial surfaces are lined by tympani form membrane - this vibrates as air rushes through which creates sound = muscles along side adjust the tension which adjusts the noise that is produced when they vibrate
what is synaptic transmission?
transmission across a neuron relies on electrical charge instead of a change in chemical concentration although the communication between different neurons is reliant on a chemical messenger which moves across the cleft (neurotransmitter)
how to prevent VQ mismatch? and example
treatment with oxygenexample of VQ mismatch as a result of pulmonary embolism:Pulmonary artery splits into multiple areas of the lungsIf it a clot forms the area is blocked and perfusion is blockedArea of high ventilation perfusion (as low perfusion)Blood normally going to this area has to go somewhere elseLow VQ in multiple other areas as perfusion has to go elsewhere as much more perfusion everywhere elseWould ultimately end in low oxygen in the blood
hat are helical fibres?
triple helical collagen molecules laid out in staggered patterncreates a banding pattern seen in collagen fibrilshelical arrangement assists with tendon elasticity
truncus arteriosus and bulbis cordis becoming aorta and pulmonary artery
true septationGet development which is all triggered by cardiac jelly and blood supplyDevelop two blobs of tissue right at the base from the Bulbis cordis and Truncus arteriosus (bulbar cushions) These cushions forms a septum which moves up and grow towards each other Waste development Aorta and pulmonary artery stay but wrap around each other
nicotinic antagonist
tubocurarine / pancuronium As an antagonist it blocks nicotinic receptors at the neuromuscular junctionmuscle relaxant in anaesthesia
what is the width of the eyelid opening controlled by?
two opposing muscle groups Eyelid closingOrbicularis oculi - facial nerve - VIIEyelid openingLevator palpebrae superioris - oculomotor nerve - IIIMuller muscle (smooth muscle) - sympathetic innervationSeveral other muscles with innervation from facial nerve - VIISensation to eyelids = branches of ophthalmic and maxillary nerves from trigeminal (V)
what airways does the mammalian lung contain
two types of airways - conducting and - respiratoryconductingbegins as a system of cavities (nasal cavity, paranasal sinuses and nasopharynx) which begin the cleansing, warming and moistening of the air drawn in through the anterior nares (nostrils)It is the sections of the respiratory tract which do not directly participate in gas exchange and instead simply allow bulk flow of air to areas which are responsible for gas exchangeRepresented by the respiratory bronchioles, alveolar ducts, alveolar sacs and alveolirespiratorythe organs allow the airflow during ventilation. They reach from the nares and buccal to the blind end of the alveolar sacs. There are specific regions with various organs and tissues to perform specific functionsUpper : nose, nasal cavity and pharynx = the conducting which serve to conduct, clean, warm and moisten the air = nose, pharynx, larynx, trachea, bronchi and bronchiolesRespiratory parts = located within the lung - respiratory bronchioles, alveolar ducts, alveolar sacs and alveoliLower : larynx, lungs, bronchi and bronchioles air sacs (alveoli
Peripheral vestibular disease
typically display head tilt, spontaneous (resting) nystagmus, strabismus, and ataxia. Falling and rolling may also be observed.have preservation of strength and have normal proprioceptive positioning responses. Because there is no brain involvement, there will be no alteration of consciousness.
variable in CSF = total WBC count cisternal and lumbar normal finding change due to bacterial infection?
under 6 microlitresindicates infection, inflammation, or bleeding into the cerebrospinal fluidSome causes include abscess or encephalitis
mucosal surfaces
upper respiratory tract, intestinal tract, oral cavity, rumen (in ruminants), superficial reproduction organs both sexes
pulse oximetry
use 2 wavelengths of light to measure oxygenate haemoglobin, measures pulse rate/strength tooTells us how well the haemoglobin is saturated with oxygenSends two different wave lengths of light across the pulsatile bed and the amount of oxyhaemoglobin is calculated at those two different wave lengths and presents percentage saturation on our device
Biochemical Separation
used for isolation of one member by working through tests
colour flow doppler
uses PW doppler in multiple location Sample multiple areas within one areaLimited by aliasing : when blood becomes turbulent / green/yellow - useful in regurgitation (murmurs)BARTBlue away from probeRed towards the probe
direct ELISA
uses antibodies to detect specific antigen in sample, there are two different approaches based on the size of the antigenmeasure antigen concentrations in various different types of samples, eg cytokines, canine rheumatoid factor, hormones (ie pregnancy or ovulation testing)
what is preload dependent on ?
venous return of bloodcentral venous pressurelow venous return = ventricular filling reduced and stroke volume reducedhigh venous return = ventricular filling increased and stroke volume increases
What does the sclerotome contribute to?
vertebral and rib cartilage - vertebral and rib cartilage, tendons, blood vessels, meninges, vertebral joints and smooth muscle of dorsal aorta
apply biomechanical principles to the locomotion of the racing greyhoundrunning surfaces
very important to the tendon - muscle units act as springs however the muscle becomes stiffer when fatigued the load is then overtaken by tendons
iatrogenic
vet causes the problem ie visiting unhealthy animal then moving over to healthy animals without changing PPEs
phototransduction
visual pigments (photopigments)Found inside membrane sacks of rods and cones. They consist of a protein (opsin) and a derivative of vitamin A
prazosin - a1 antagonist
what has happened to NA's effect on ABP/HRNoradrenaline can act on alpha and beta receptorsIn the presence of prazosin the heart rate increased to the same level so there are no a1 receptors presentBlood pressure
Define a neurotransmitter and name the major classes of neurotransmitters
what is a neurotransmitterMust be synthesised in a neuron and required enzymes must be presentMust be released in sufficient quantity to release a postsynaptic responseThey need to be inactivated or removedExogenous administration should mimic the action of the exogenously released neurotransmittermajor classes of neurotransmitter- amino acid- biogenic amines- small molecule neurotransmitters- neuropeptides
signs of lower airway disease
wheezingcoughingexpiratory dyspnoea
atrioseptum defect
when foramen ovale is not shut
shunt function in stress
when stressed pumps straight towards essential organs and is able to do this by moving away from non-essential organs
Explain the resting membrane potential and the action potential
when the neuron is at rest its cytosol along the inner membrane is negatively charged compared with the charge of the outside - 65 to - 70 mV (+ outside - inside)action potential is when the membrane is depolarised caused by a positive charge applied to the inside of the membrane
respiratory alkalosis (acute)
when the pH has gone upcarbon dioixde decreases due to an increase in breathing/ventilation caused by : CNS disease, pregnancy, over enthusiastic ventilation and pain overtime (chronically) renal compensation excretes carbonate ions which may be effective in dogs
grey matter
where the cell bodies sit including :Neurones.Synapses.Dorsal horn - sensory neuronsLateral horn (Th-L only) - autonomic neuronsVentral horn - motor neurons
API strip
which has lots of small wells with different culture media that assess different reaction when inoculated with the bacteriaLHS range of specific assays/reactionsRHS assess ability to ferment different compoundsThe wells are scored for if they react then this code is read off on an interpretation table
What happens to heart rate as we increase ACh
will cause the heart to become tachycardia as we have a lot of cholinergic receptors in the heartWe need to protect the receptors in the body by using atropine from too much Ach It is an antagonist at the receptor so Ach can replace antagonist from receptor
bronchealveolar lavage (BAL)why do we do it
with the cat under GA, warm saline is instilled into the bronchi via a sterile urinary catheter. The fluid from the bronchi is then suctioned out and submitted for culture and sensitivity and cytological examination.Bronchial cytology is variable, with predominant cell types including eosinophils, neutrophils and macrophages. These are not pathognomonic for feline asthma however, as eosinophils can be found in normal cat airways. Culture and sensitivity helps to rule out infection.
Left-sided peripheral vestibular lesion
you would then expect a fast phase nystagmus away from the lesion side (i.e., to the right), a head tilt to the left (same side as the lesion), and potentially falling/rolling to the left side as well. It is also common to observe an ipsilateral ventrolateral strabismus or eye deviation due to interference with ascending vestibular pathways (i.e., MLF).
Koch's postulates
1884 1. The organism must be found in all animals suffering from the disease, but not in healthy animals.2. The organism must be isolated from a diseased animal and grown in pure culture.3. The cultured organism should cause disease when introduced into a healthy animal.4. The organism must be re-isolated from the experimentally infected animal.
4 factors influencing lung development
4 factors that influence lung developmentIntra thoracic space - size available for lungs to develop inIntra uterine space - size of uterus, amount of amniotic fluidFoetal breathing movements - frequency and intensityLung liquid production - how much is producedAffect any of these = underdeveloped lungs - neonatal support is needed
lifecycle of toxocara canis
4 possible scenarios1. Typical way Faecal oral route of transmission Infected larvae ingested - L1/L2 Develops in small intestine2. Alternative route Absence of right host Paratenic host used - mouse Infection can be acquired when the dog ingests paratenic host - embryonated eggs L2- adult in dog intestine3. Development in pups = memory gland L2-L3 ingested in pups Puppy under 5 weeks Large number of larvae in muscles L3 ingested by suckling pups Hormonal changes cause reactivation of larvae which migrates into pups via transplacental migration4. Development in pups - transplacental migration of L2 to foetal liver neonatal lung
what are the limits to the length-tension relationship
: excessive stretching, Laplace's law : more wall tension is required to generate the same internal pressure in a large sphere then it does in a small one. Enlarged hearts makes it harder for the muscle mechanically to empty the chambersSeen in dilated cardiomyopathy in dogs
how do the tears drain?
= Drain into two cuniculi which join with the lacrimal sac= that then forms nasolacrimal duct goes down to nasal punctum-The nasolacrimal duct (also called the tear duct) carries tears from the lacrimal sac of the eye into the nasal cavity. The duct begins in the eye socket between the maxillary and lacrimal bones, from where it passes downwards and backwards.
diagnostic tools for respiratory tract - bronchoalveolar or tracheal wash
= commonly used to asses the respiratory health of race horsesBronchioalveolar wash (endoscope)The cells have surfactant on top it looks frothy and opaque showing how many white blood cells you haveTracheal wash (natural u-bend in equine trachea - endoscope)TransparencyColour (number WBCs, RBCs)Viscosity (mucus)
minimal media
A basic salts based growth media often with a single carbon source.(Simple salts buffer, metal salts and a carbon source other supplements added as required, only really used in research as it allows strict control of the exact content of media)
microhaematocrit
A capillary that we will fill with blood and then centrifuge which separates into plasma, buffy coat (beige or buff colour, white cells and platelets), erythrocytesThis measures the ratio of the volume occupied by packed red blood cells to the volume of the whole blood= packed cell volume or PCV
membrane attack complex
A central effector mechanism of complement and innate immune responseThe endpoint of all 3 activation pathwaysMAC or terminal complement complexComposed of C5B, C6, C7, C8 AND C9Forms a pore in membrane which opens the bacterial cell cytosol Dramatic loss of cellular homeostasis Disrupts proton gradient (signalling) Penetration of host lysozyme and other proteases
what happens at birth
A change in pressure in the right atrium and increase in pressure in LAWe want blood to go into the lungs nowSeptum secundum and septum primum tightly appose - close intra-atrial septum
The anion gap
A construct used in metabolic acidosis as cliniciansEnables us to work out if the body has had some additional acid added to itAdding up all the cations in the body (sodium and potassium) and subtract the anions (chlorine and bicarbonate)The normal anion gap is ~17 mmol/LThis gap sometimes get bigger which tells us that there has been an addition of acid to the bodyHelps us to make a decision as a clinician - diabetic ketoacidosis or when patients get poisoned= helps us to figure out what the cause is
Nutrient media
A medium with all the basic (general) requirements for growth but without specific supplements. (Often meat/yeast extract so a complex mix of peptides, ions and biochemical intermediates & salt)
nutrient media
A medium with all the basic (general) requirements for growth but without specific supplements. (Often meat/yeast extract so a complex mix of peptides, ions and biochemical intermediates & salt)
selective indicator media
A mix of extra nutrients as well as inhibitors for unwanted bacteria alongside indicators to locate the desired bacteria
What is commensalism?
A relationship in which one organism benefits and the other is neither helped nor harmedfungi and protozoa can be involved in complement too as well as bacteria
brachycephalic mesocephalic dolicephalic
A relatively broad, short skull with the breadth typically 80% of the length. = Pug, French bulldog, King Charles Spaniel, Chow chow, PekineseA head of medium proportions to neither extreme, with a broader back skull compared to the muzzle.= Springer spaniel, Border Collie, Beagle, DalmationThe heads are long and narrow, with an extended slim muzzle.=whippet, rough collie, german shepherd, great dane
host recognition of pathogens
A specific combination of PAMPs is expressed by each pathogenPRR repertoire is different for each cell type of immune systemPRR distribution and levels change in response to infectionReceptor pathways have been shown to interact with each other - complex signalling network
host recognition of pathogens involves several levels of complexity
A specific combination of PAMPs is expressed by each pathogenPRR repertoire is different for each cell type of immune systemPRR distribution and levels change in response to infectionReceptor pathways have been shown to interact with each other - complex signalling network
blood volume and viscosity affecting blood pressure
A sufficient amount is required to overfill the arterial systemViscosity : blood is 5 x more viscous than water Increase viscosity increases resistance and more work for heart
label the thoracic radiograph
A- aortaB- caudal vena cavaC- trachea- deviating away from the vertebral spine- heart enlargement would push it upD- left cura of the diaphragmE- right cura of the diaphragmF- heartG- cranial lung lobeH- liver
Diastasisdiastole
AV valve openVentricles continue to fill with bloodFollowed by atrial systole
Cardiac enlargement
AV valves leak more, oxygen needs go up, oxygen supply goes down, cells die- not replaced, scar tissue forms contractility falls further
Rapid ventricular fillingdiastole
AV valves openVentricles relax causing their pressure to fall below their respective atrial pressuresThe AV rapidly open and passive ventricular filling beginsVentricular filling is normally silent - third heart sound S3 is normally heard during rapid ventricular filling
Atrial Systolesystole
AV valves openSemilunar valves closedAs the atria contract the pressure within the atrial chamber increases which forces more blood flow across the open AV valveRapid blood flow into ventricles
haemodynamic theory
Abaxial movement of the lateral cartilages under load creates negative pressureBlood vessels inside the lateral cartilages are well developed in horses with good feetBlood vessels on axial side of lat.carts in horses with poor feetThe idea is as the pedal bone drops inside the foot there is a negative pressure above the pedal bone which sucks blood from out of the laminae into the blood vesselsAs the foot is lifted off the ground the pedal bone rises and pushes blood out into the veinsNo heart in the foot so blood needs to get up the leg the theories of blood are aboveInternal structural support of the foot : cushions, blood 'pump, multiple theories, sensory nerves - proprioceptive functionStatic pressure taken through the laminae
factors influencing ventilationlung compliance
Ability of lungs to be stretchedElasticity of tissue in the lungs and thoracic cageSurface tension in alveoliWhich structures contribute to elasticity of the lungs?Coiled collagen fibresLung elastic fibresIntercostal muscles, joints and pleura of the thoracic cagePathologyReduced lung complianceScar tissue in lungs or pleuraIncreased lung complianceCan aid inspiration but if prolonged can reduce elasticity of lung
What is the journey that a drug takes?
Absorption (stomach/small intestine)Distribution (blood)Act on targetMetabolism (liver/lungs)Excretion (GI tract/kidney)
Nicotinic agonists
AcetylcholineNicotine (CNS, ganglion)Suxamethonium (succinylcholine)nicotinic acetylcholine receptors (nAChRs)- They are found in the central and peripheral nervous system, muscle, and many other tissues of many organisms.
Bronchoconstriction Parasympathetic Nervous System
Acetylcholine binding with muscarinic receptors - does the opposite or adrenalineM3 receptors Decrease cellular cAMP Increased mucus secretion Contraction of bronchial smooth muscleM1 receptors - increased mucus secretion
neuromuscular junction with nicotinic receptors present process
Ach will be released : affecting respiratory centre and ganglionPresynaptic nicotinic receptors operates on positive feedback :Facilitating further ACh release from presynaptic side
stages of learning and memory
Acquisition Registering information into a buffer for analysisEncoding Processing of information come to be storedConsolidation Short-term to long-term memory; creating stronger representationStorageResult of acquisition and consolidation to create a permanent recordRetrieval Use of stored information to perform a learned behaviour
Microglia
Act as phagocytes, eating damaged cells and bacteria, act as the brains immune systemspecialized macrophages that are mobile and control inflammation
ANS innervation of the heart
Act on the atrium - noradrenalineCauses it to contract more quickly or with more contractionAch - largely effects heart rate - slowing
Adrenal cortex and CRH
Adrenal cortex secretes hormones eg stress hormones - glucocorticoids like cortisolWhen stressed brain stimulates hypothalamus to release corticotropin-releasing hormone (CRH) CRH then carried to the anterior pituitary gland via portal system and stimulates adrenocorticotropic hormone (ACTH) to be released = causes release of corticosteroid eg cortisol
Adrenal medullaNerve fibreNeurotransmitterDesignationReceptor
Adrenaline (Epinephrine)Adrenergicα and/or β
use of adrenoreceptor agonist?
Adrenaline = cardiac arrest, anaphylaxis (allergic reactions) Not ideal as you will have problems with blood flow but best for allergic reactionsSalbutamol = asthma bronchi will dilate β2Xylazine, medetomidine = sedative analgesic lowering the blood pressure α2 Act in the periphery in the CNS mainly a postsynaptic effect Usually used in minor surgeries for instance
Dictyocaulus spp. (lungworms)
Adult nematodes found in the trachea and bronchi causing parasitic bronchitisDeposition of eggs/newly hatched larvae may lead to parasitic pneumoniaD. viviparus (cattle, camelids and deer) - boot shaped spicule, male has copulatory bursa and female will be bigger (two ends in male there is another structure)D. filaria (sheep and goats)D. arnfeldi (donkeys and horses)
treatment of heartworm disease in dogs
Adult wormsMelarsomine dihydrocideMicrofilarieIvermectin, milbemycinUse of adulticidesDead worms may induce significant inflammatory immune reactionsThis can lead to pulmonary thromboembolism (clot in pulmonary artery)Disseminated intravascular coagulationProbably some embolisation is expected following adulticide treatmentIncreased exercise can cause pulmonary rupture and increase severity of heart worm disease
Describe the impact of nutrition and respiration of bacteria- types of chemoheterotroph
Aerobe- uses oxygen aa a terminal electron acceptor.Strict aerobe- need oxygen to grow.Facultative anaerobe- can use oxygen as a terminal electron acceptor or switch to use other acceptors.Anaerobe- cannot use oxygen, has to use other terminal electron acceptors.Strict anaerobe- will not grow in the presence of oxygen, as molecular oxygen is a potent oxidiser and these bacteria do not have the protective mechanisms against it.Bacteria can switch different systems on and off depending on availability.
Explain the spatial segregation of information pathways within the spinal cord
Afferent and efferent regionsOrganised as afferent and efferent regionsSensory top - dorsal part of grey matterBottom half motor - ventral part of grey matterEfferent = motor and afferent = sensory
in what circumstance is the sympathetic NS activated?
After the amygdala sends a distress signal, the hypothalamus activates the sympathetic nervous system by sending signals through the autonomic nerves to the adrenal glands.Under conditions of stress
two main types of receptor drugs?
Agonist : drugs that bind to receptor and activate themAdrenalineAntagonist : drugs that bind to receptors but do NOT activate themRanitidineAntagonists block the effects of agonists
Explain the effects of exercise and training on the respiratory system
Aim is to get more oxygen in and to get rid of excess carbon dioxideIncrease respiratory rateIncrease tidal volumeThere is a tipping rate where ventilation keeps on going but oxygen uptake to muscle starts to plateau - VO2 maxNo more oxygen going in but exercising is continuing so you will begin to produce lactate
middle ear
Air filled cavity in temporal bone containing ossicles transferring tympanic membrane vibrations to inner earOssiclesMalleus, incus, stapesThey act as levers to transmit the sound wave vibrationsTympanic bullaResonant cavityEustachian tube openingAuditory tubeConnects middle ear with pharynxThe purpose is to equalise the pressure on the two sides of the tympanic membraneGuttural pouches are§ out-pouchingFunction is to transmit the fluid to inner earIncreases pressure and reduces amplitude of vibrations through the ossiclesStapes pushes on fluid in inner ear
Describe the radiographic appearance of pneumothorax
Air in plural space outside of lung, looks much blacker, heart not touching sternum anymore.
functional division of the lungs and air sacs
Air sacs - gas movement Poorly vascularised and not involved in gas exchange Move air aroundLungs - gas exchange Just there for gas exchange Stiffer than mammalian due to cartilage Unidirectional flow
describe the higher order processing of visual information
All information comes from ganglion and projects to surrounding areas (17,18,19)Area 17 Novel forms of visual fields: Simple cells - mapped with spots of light Complex cells - respond to bars of light or an edge specific orientationHypercomplex cellsIntegrated response bilaterally - from both eyes and brought together in area 17 Cells tend to be organised in columns of similar fields Doesn't really do colour
What occurs to the valves at the end of ventricular diastole
All valves are closed until pressure in the ventricles exceeds pressure in the aorta/pulmonary artery.
In a sandwich ELSIA, what would happen there was no washing steps after the detection antibody was added to the well?
All wells, including the negative control wells, would show uniform overdevelopment
functions of conduction system
Allow more rapid conduction of action potentials than is possible through contractile muscle cells = Enables entire ventricular myocardium to contract simultaneouslyTo delay impulse transmission between atria and ventricles = Allowing them to fillOnly connection between atria and ventricles
stained smears
Allows looking at bacteria in blood abscess and bacteriaNot many stains are species specificGram stain = gram positive and gram negative bacteria
In what direction will blood flow across the following structures in an adult? Patent ductus arteriosus
Allows portion of oxygenated blood from the left heart to flow back into the lungs by flowing from the aorta to the pulmonary artery
What is oedema?
An excessive accumulation of interstitial fluid, may be free fluid in cavities.Localised or generalisedCaused by an increase in hydrostatic pressure, damaged vessels, decrease in blood protein.Starling's forces out of balance- increased (outward) filtration pressure, decreased (inward) absorption pressure- leaky vessels.
reduced systemic oxygen to the lungs causing hypoxia
AnaemiaHeart disease Oxygen in blood and if the heart is not pumping sufficiently will not get to tissuesHypovolaemia Not enough blood volume to support circulationExtreme vasoconstriction Periphery is shut down so you can send blood to major organsSepsis
anaemia
Anaemia - condition in which the capacity of the blood is to transport oxygen is reducedReduced number of circulating erythrocytesReduced amount of haemoglobin per erythrocyte
Congenital hydrocephalus
Animals are born with water that takes over the brainDisruption of CSF containing systemExpansion of the ventricles due to obstruction and back up of CSF and/or loss of CNS tissue (pressure atrophy or necrosis or hypoplasia)Genetic defect - unknown
urease test
Another pH based indicator testUrease breaks down urea to carbon dioxide and ammoniaIndicator in the slope of solid media is more red the more alkaline it is A more yellow result the more acidic
what is serotyping?
Antibodies are used and attach to surface structures. The reaction between an antibody and antigen is extremely specific and so agglutination of bacteria with the antigen to the antibody occurs in the sample, showing a positive result.Defining closely related bacteria using antibodies which bind known antigens of those bacteria
name the openings in the diaphragm for?aorta and thoracic duct?
Aortic Hiatus - the most dorsal opening, contains the aorta, azygous vein and thoracic duct.
Rapid Ejectionsystole
Aortic and pulmonary valves open - AV valve remains closedPressure in ventricles will exceed that of the aorta and pulmonary arterySo ventricles contractsVentricular ejectionBlood leaving ventriclesGoes into the aorta and pulmonary arteries from left and right ventricles
Describe the appearance of the trace through one cardiac cycle on a Wiggers diagram
Aortic pressure- increased during systole, decreasing during diastole.Ventricular pressure- high increase during systole which peaks at the middle and reduces to a steady low value during diastole. Left is higher than right.Atrial pressure- steady low pressure, slight decrease at the end of diastole and a slight increase at the start of systole.
Explain the structure of motivated behaviour
Appetitive- various initial motor patterns that bring the animal into a situation where it was likely to encounter a "stimulus". As if the animal had an "appetite for the stimulus".Phase I: No evidence of "stimulus" (e.g. prey, food) - non-directed.Phase II: Stimulus detected (e.g. smell, sight of prey, food), eventually chasing and capturing prey/ finding food - directedPhase III: Consummatory (killing prey, eating)Phase IV: "Satiation"Consummatory- stereotyped, expected response to a stimulus which achieves what it was sought out to do - performances satisfies the 'appetite' of the animalFeedback may result in more flexible behaviour. But generally the flexibility and variability of behaviour decreases as you go through the phases.
Describe the different types of platelet granules
α (alpha)- most numerous. Growth factors- insulin-like growth factor, platelet-derived growth factor, transforming growth factor beta (TGFb). Von Willebrand factor. P-selectin,thrombospondin, fibronectin. Platelet factor 4 (heparin-binding chemokine).δ (delta or dense)- contain ADP or ATP, calcium, serotoninγ (gamma)- similar to lysosomes, contain hydrolytic enzymes- breakdownλ (lambda)- contents involved in clot resorption
Adrenoreceptors and examples of localisation
α1-Receptor: blood vessels (vasoconstriction)α2-Receptor: blood vessels, nerve terminals (autorecepors) - inhibition of transmitter releaseβ1 receptors: heart (tachykardia), increased forceβ2 receptors : blood vessels (vasodilatation), bronchi (bronchodilatation), liver (glycogenolysis)β3 receptors : fat (lipolysis)
• Sympathetic innervation (release Of NA)
• Noradrenaline • Increase HR . cardiac (could be a or • Vasoconstriction (could be a or • NO baroceptor reflex • Isoprenaline • Increase HR. cardiac output in heart) • Reduced BP: Vasodilation ("adrenoceptor in vasculature) • Prazosin (a1 antagonist) • No effect HR (a 1 adrenoceptors do NOT control HR) • Block NA indtned increase in blcx»d pressure (a 1 adrenoceptors Induce Vas o co • No effect isoprenaline — confirms selectivity of prazosin
What function do the arachnoid villi perform?
Act as one-way valves for the flow of CSF into venous blood and hydrostatic pressure is the main stimulus that causes these valves to openPermit the one way flow of CSF from subarachnoid space to venous circulation
basal ganglia
Basal nuclei- caudate nucleus, putamen, globus pallidusFunctions are caudate nucleus and involved in motor regulationParkinson's is a disease affected by faulty basal ganglia
bipolar cells
Between photoreceptors and ganglion cellsGating of information
What is the significance of this in relation to slaughter techniques?
Can cause issues when ritual slaughter is concerned as take longer for loss of consciousness from slashing neck - animal welfare issuevenous drainageUnlike other regions of the body, venous drainage in the brain does not follow the arterial supply.The veins of the brain are valveless and drain into the dural venous sinusesThe dorsal sagittal sinus (superior in humans) lies in the falx cerebri and divides at its caudal end into the transverse sinuses which sit in the tentorium ceribelli
explain concept of lateral inhibition
Depending on whether the light hits the edge of the cell or the middle of the cell the cell reacts differentlyIf it hits both no response at allOpposite reactions between hitting middle and hitting edgeIt improves edge detection and localisation
inner ear
Encapsulated in temporal bone - made up structures that contribute to both hearing and balanceCochlea\Three coiled, fluid filled canalsThey are stimulated by soundVestibulum and semi circular canals3 fluid canals : uppeEncapsulated in temporal bone - made up structures that contribute to both hearing and balanceCochleaThree coiled, fluid filled canalsThey are stimulated by soundVestibulum and semi circular canals3 fluid canals : upper, middle and lowerUpper and lower canals are filled with perilymphMiddle canal filled with endolymph Higher in potassium Has a positive electric potentialSensory cells sit on basilar membrane in middle canal Hair cells and microvillir, middle and lower
endotherms vs ectoderms for stable body temperature
Endotherms, such as birds and mammals, use metabolic heat to maintain a stable internal temperature, often one different from the environment.Ectotherms, like lizards and snakes, do not use metabolic heat to maintain their body temperature but take on the temperature of the environment.
transmission risk of TSE
Fall into two groups with regard to transmissionVery hard to transmit between susceptible hosts All human TSEs BSE MSETransmitted through medical procedures or through ingesting of contaminated foodReadily transmitted Scrapie in sheep / goats CWD in cervidsTransmitted through direct contact and environmental reservoirs
To where does fluid flow into from the fourth ventricle?
From the lateral ventricle to the third ventricle through the interventricular foramen
Imepitioin (pexion)
GABA receptor partial agonist so slightly different from benzodiazepinesLess side effects
describe functional arrangement of ganglion cells
Ganglion cells in dark and light and along edgesSpikes on each ganglion cell show which cells are having greatest responseOnes on the edgesCells will fire when lights hit themOff centre and on centre ganglion cellsOn centre will fire when centre of circular area is illuminated and the periphery is dark Problem is they only fire for certain amount of time Illumination period followed by suppression period causing you to not register anymore Suppressed when periphery is lit upOff centre which fire most when periphery is illuminated and centre is dark
metencephalon
Hind brain CerebellumBalance Coordination of movementArousal (outgrowth of pons)PonsPart of brainstem
negative feed back
Input from CNS Environmental stimuliSensory cells around third ventricle Internal stimuli - salt concentration etc The stimuli both stimulate processes in the hypothalamusCircadian rhythmEpisodic secretionNegative feedback control Short loop Long loopACTH reaches adrenal cortex and stimulates release of cortisol
cataplexy
Lack of orexinergic control activates a nucleus in the pons that inhibits lower motor neurons
transduction in hair cells
Movements will affect stretch sensitive ion channels at the tip of the sensory hairsTip links connecting cilia open the K+ channels As the hairs get pushed against tectorial membraneLeads to depolarisationOpens the voltage gated Ca2+ channels open Influx of calcium causes release of neurotransmitter by exocytosis
fluid in the endolymph function
Provides a structure for utricle and sacculeProduces fluid that flows in semi-circular canals
association cortex
Receives information rates it against other information it has and previous experience and responds with an appropriate response
paleocortex
Related to olfactory sense large part of olfactory system (sense of smell)Quite prominent in the domestic rabbit
Henderson-Hasselbach Equation
Relates to the pH, the pKa and the ratio of the concentrations of the proton acceptor (A-) and the proton donor HA species in a solutionClinical implications of this equation and helps understand why drugs work in specific circumstances
role of retina
Rods = identify shapes of objects in low light levels (topic vision)Cones = detect colourThey have different sensitivity ranges and different distribution within retina
TSE confirmatory tests
TSE confirmatory testsWestern blots or ELISAsPrPSc is highly resistant to proteasesTSE negative = no bandsTSE positive = three bandsAll confirmatory tests are post mortemCan test lymphoid tissue: humans- tonsil, appendix ovine RAMALT and third eyelid
What is the ARAS
The ascending reticular activating systemmain brain structure that maintains wakefulness and arousal
blood supply to the brain
The blood supply to the brain comes from the cerebral arterial circle (aka Circle of Willis), which lies ventral to the hypothalamus. In the dog and horse, blood supply to this structure comes mainly from the basilar arteryThe arterial circle is joined caudally by the internal carotidIn other species, the arrangement is more complicated, and in the ox, blood enters the arterial circle via maxillary artery and vertebral artery pathways.
what is the vestibular system made up of?
Two functional units - semi circular canals and otolith organs = utricle and sacculeCupula = gelatinous mass which sits within semi circular canalSensory hair cells in it which are similar to those in the earDeviating the hairs causes depolarization = transmission of infoFluid deviates the cupula to one side distorting the hair cells Transmission of info If fluid stops moving cupula returns to initial position
What happens to your thermal set-point when you have the 'flu' or Covid -19
When fighting an influenza infection, the body may raise its temperature to make it difficult for the virus to replicate. This abnormal increase in body temperature is known as a fever. A fever is part of the immune system's response to an infection and is a typical flu symptom
base
a proton acceptor decreases H+ concentration in solution
acid
a proton donor increases the H+ concentration in solution
buffer
a substance (solution) that resists change in pH when small amounts of acids or alkalis are added
what are deep cerebellar nuclei neurons?
all excitatory to nuclei of pyramindal and extrapyramidal systemsthese nuclei are inhibited by Purkinje cells and excited by collaterals of afferent fibres.
amacrine and horizontal cells
allow for integration at retinal level
peduncles
allows information to transferallow fibres to enter/leave cerebellumrostral - visual reflexes, efferent and afferentmiddle - afferent onlycaudal - afferent and efferent, sleep and balance
archicerebelllum = 1
balance and equilibriumdeveloped in fish first
three vesicles of brain
forebrain, midbrain, hindbrain
where is the sleep centre believed to be
in the hypothalamus (vl POA - ventral lateral pre-optic area)
what are the components of the epithalamus?
largely the pineal gland= its function is to produce melatonin and plays a role in circadian and seasonal rhythmsparaventricular and habenular nuclei- it is the most dorsal part of diencephalon- rostral to mid brain
histamine in arousal system
maintains wakefullnessanti-histamines make you sleepy but newer ones do not reach the brain
thermoneutral zone
the range of ambient temperatures without regulatory changes in metabolic heat production or evaporative heat loss
What is the location and components of the diencephalon
the thalamus and hypothalamus are the principle structures and the main subdivisions are the epithalamus, thalamus and hypothalamus it is between the telencephalon and mesencephalon and is part of the forebrain
what is acidity directly related to?
to the concentration of H+ where the concentration is kept constant