Cardiovascular 4, 5 and Practical Flashcards
What are the 4 divisions the vascular system?
What are the three layes of an artery?
How do different artery’s layers differ?
Arterial, Capillary, Venous, Lymph vessels
Intima- endothelium
Media- thick, elastic and smooth muscle cells
Adventia- Collagen, connective tissue
Elastic- elastic laminae in media
Muscular- fewer muscle layers, no elastic laminae
Describe different capillaries in 3 words?
What is the thickest layer in veins?
- *Continuous**- epithelium
- *Fenestrated**- endocrine glands, glomerulus
- *Porous**- liver, bone marrow, spleen
Adventia
What is an aneurysm?
What can cause aneurysms?
What are the potential consequences?
Localised dilation of a thinned and weakened portion of a vessel- usually arteries
Copper defificncy pigs- needed for elastic tissue
Parasitic infestations- Spirocerca lupi
Disecting aneurysms- birds, disruption of intima
Usually rupture
Other then aneurysms what can cause vessel rupture in Cows and Horses?
Horses-
sudden rupture of ascening aorta due to trauma to ventral thorax from fall, death from cardiac tamponade
rupture of internal carotid artery into adjacent guttural pouch
Cows-
Rupture of middle uterine artery during parturition- uterine torsion or prolapse
What causes arterial hypertrophy?
What can cause it in all species as well as specifically cats and cows?
From sustained increase in pressure or volume
Muscular arteries are mainly affected with hypertrophy of smooth muscle
All species- CV anomalies that shunt blood left to right lead to pulmonary hypertension and hypertrophy
Cats- pulmonary arteries- parasitic infections
Cows- Pulmonary arteries- high altitude
What diseases cause arterial medial calcification?
How do they grossly and histologically appear?
Where is arterial intimal calcification normally found?
Concurrent endocarcial mineralization and fibrosis-
Calcinogenic plants, vitamin D toxicosis, renal insuffiency, Johne’s disease
Grossly- solid, dense, pipelike structures with raised, white, intimal plaques
Microscopically- prominent basophilic, granular material deposits, occasionally admixed with Iron
Normal in subendothelium of muscular arteries
What is fibrinous necrosis?
Describe its pathogenesis?
What are the aetiologies in Pigs/Dogs?
Deposits of amorphus homogenous, eosinophilic protein material composed of serum proteins and fibrinogen
Pathogenesis- Endothelial and muscular damage of the arterial wall with extravasation of proteinas and deposition in the vessel wall
Pigs- Selenium/Vit D deficiency, Oedema disease
Dogs- uraemia
What is thrombosis?
What are the predisposing factors?
Process of intravascular coagulation during life
Endothelial damage- arteritis, parasites
Turbulence/stasis
Hypercoagulability- high fat diets, congenital
What is DIC?
What can cause it?
Why does it lead to haemorrhage?
How does it appear microscopically?
Disseminated intravascular coagulation- Clotting phenomenon due to endothelial damage with exposure of subendothelial collagen and subsequent platelet aggregation and IV activation
Causes- Endotoxaemias, Viraemias, Dirofilarioasis, Tumours, Shock, haemolysis, extensive necrosis (burns)
Extensive clotting depletes coagulation factors resulting in widespread haemorrhages
Microscopically- numerous fibrin thrombi in arterioles and capillaries
What is an embolism?
What are the different causes of emboli?
How can they be distinguished from other clots PM
Occlusion of arteries from lodgment of foreign material
- Septic- vegetative endocarditis in the lung or myocardium
- Parasitic- fragments of dead intravascular parasites- dirofilaria
- Fat- bone fractures
- Fibrocartilagenous- spinal arteries of dogs resulting in posterior paresis- infarction of spinal cord
- Thromboembolism- pulmonary artery tree- hypercoag, sepsis etc
Clots are easily removed PM
What are the different causes of vasculitis (arteritis)?
How does it appear grossly and microscopically?
Haematogenous dissemination
Local extension of supprative-inflammatory processes
Immunomediated processes
Parasitic infections
Gross- Medium-sized arteries appear thick and tortuous, associated with haemorrhages, aneurysms and thrombosis
Microscopically- fibrinoid necrosis and inflammation of the intima and media
What are the different aetiologies of vasculitis and give some specific examples
Viruses- BVD, FIP, Bluetongue, EIA
Parasites- Strongylosis, dirofilariasis
Bacteria- Salmonellas, Hemophilus
Fungi- Aspergillus
Immunomediated- SLE
What are the viral causes of vasculitis and where is it found?
- Blue tongue in sheep- orbivirus: blood sucking insects- polyarteriosis centered around intima- haemorrhage at origin of pulmonary artery
- Equine viral arteritis- polyarteritis media and adventia also- petechia, subcut oedema, hydrothorax/peritoneum
- MCF- gamma-herpesvirus- polyarteritis and periarteritis
- EIA- poly/periarteritis
- FIP- coronavirus- Pyogranulomatous vasculitis
What emerging parastite in the dog can cause arteritis?
Dirofilaria immitis
Mosquito vector
Adult worms in pulmonary arteries of dogs
Villous pulmonary endoarteritis and obstruction- RV hypertrophy
What 4th stage larval parasite is found in the mesenteric arteries?
Strongylus vulgaris in horses
Intense focal inflammation
Aneurysm
Thrombosis
Infacrtion
What is phlebitis?
What can cause it?
What omphalophlebitis and what causes it?
Inflamation of veins
Systemic infections- salmonellosis
Local infections- hepatic abscesses
Intravenous injection sites
Omphalophlebitis- inflammation of the umbilical vein
Common in neonatal farm animals- bacterial contamination, septicaemia
What are the three tumours occuring in the vascular system?
Haemangiomas- well circumscribed, benign of well differentiated endothelial cells
Variably sized vascular spaces filled with erythrocytes and lined by single enothelial cells
Haemangiosarcoma- malignant neoplasm of endothelium, any location, typically RA/spleen
Gross- large, red, nodular
Histo- irregular vascular clefts, channels, high mitotic rate
Haemangiopericytomas- vascular wall tumours- dogs- multilobulated, occuring around the joints of limbs- white and firm- whirls of fusiform cells
What is meant by vegetative?
Abnormal growths (vegetations)
A 6yo male boxer died after an acute deterioration following a period of CHF that had been managed medially
Describe the gross lesion
MD
Origin of the lesion
At the base of the heart there is a single focal mass, approximately 15x10cm, an ovally irregular chape, well demarcated, pale tan with reddened areas appears firm
MD- heart chemodectoma
Origin- chemoreceptors of the aortic/carotic bodies
A 4 day old foal died following signs of encephalopathy
Describe the gross lesions
MD
Explain the encephalopathy
Gross- at the centre of the interatrial septim there is a 2cm circular defect with a narrow band of tenuous membrane around the periphery
MD- persistent foramen ovale
Mixing of deoxygenated blood with oxygenated causing hypoxia leading to ishacemic encephalopathy
10 week old female pig exhibited signs of shallow respiration and unwillingness to move- discovered dead
Describe the gross lesion
What is the MD?
What are some possible aetiologies?
Gross- Heart, diffusely on the epicardium surface a thin layer of yellow fibrinous material, appears sticky
MD- fibrino-purulent epicarditis, moderate, subacute
Aet- Haemophilus parasuis, Streptococcus suis
6 mo male pig with signs of dyspnoea and pyrexia with associated laemeness and neck pain. Euthanised
Gross description?
What could the MD be?
Heart- on the aortic valve is covered in raised nodules which are multifocal to coalescing from 3-5cm, they are a dark red colour and appear firm
Vegetative endocarditis, severe subacute- E.coli
Hard without histology- Endocarditis
6yo Lab bitch, CHF for 6 months
Give a gross description
What is the disease?
Gross- heart- ventricles are diffusely enlarged and dilated as well as a general cardiomegaly with thinning of the ventricular walls, causing a globe shape, appear softer texture
Dilated cardiomyopathy
Why is canine parvovirus only found in the heart of very young animals?
Parvovirus can only replicate in dividing cells, cardiomyocytes only divide in very young animals
