Vascular System Flashcards
Vascular lesions
-edema and congestion
-hemorrhage
-thrombosis
-ischemia/infarcts
Degenerative disease of arteries
- arterioschlerosis
2.Atherosclerosis - Arterial hypertrophy
- Aneurysms
- Arterial medial calcification
Arteriosclerosis
HARDENING OF ARTERY WALL
-loss of elasticity
-luminal narrowing
-occurs in elastic arteries like abdominal aorta, and occur commonly at branching sites
Arteriosclerosis
-intima with raised corrugated white plaques
-plaques may have calcium deposits
Atherosclerosis
-excessive cholesterol deposited in arterial walls
-rare in animals
-linked with heart attacks (myocardial infarcts) in humans
Atheromas
-cholesterol plaques in intima and media of arteries
-common in coronary arteries (heart attack) and cerebral arteries (stroke)
When does Atherosclerosis occur in animals?
-most commonly seen in hypothyroid dogs with hypercholesteolemia or diabetes mellitus
-also seen in pigs, psittacine birds and pigeons fed high lipid diets
Atherosclerosis
-thick arteries on heart
-Histo: plaques with foamy, lipid laden macrophages, cholesterol, fibroblasts, smooth muscle proliferation
Arterial hypertrophy
-hypertrophy and hyperplasia of the smooth muscle of muscular arteries
-results in loss of elasticity, narrowing of lumen, and increased resistance
Broad cause of arterial hypertrophy
Hypertension
High altitude (brisket disease)
Caused pulmonary hypertension, medial hypertrophy of pulmonary arteries, increased flow resistance, dilation hypertrophy of right ventricle=Right heart failure
-also see ascited and SQ edema
Pulmonary hypertension and arterial hypertrophy in cats
- Dirofilaria immitis
- Renal disease
- Some association seen with Aelurostrongylus absstrusus (although idea mostly abandoned because seen in uninfected)
Aneurysm
-localized weakening and dilation of blood vessels, particularly elastic arteries and to a lesser extent veins
-prone to rupture causing hemothorax, hemoabdomen, hemopericardium, brain hemorrhage
Types of aneurysms
1.Saccular aneurysm
-spherical/ovoid dilation of blood vessel (like a balloon)
- Dissecting aneurysm
-a tear in the intima allowing blood to enter space between the intima and media, dissecting wall of vessel
Common causes of aneurysms
- Strongylus vulgaris in horses (cranial mesenteric artery, aorta)
- Spirocerca lupi in dogs
- Copper deficiency in mares and pigs
- Trauma
5.Atherosclerosis and hypertension in humans
Saccular or fusiform aneurysm
Etiology: strongylus vulgaris
saccular or Fusiform aneurysm
Etiology: Spirocerca lupi
Arterial medial calcification
-Arterial calcification
Causes:
- Hypervitaminosis D or ingestion of toxic plants containing vitamin D analogs
- Chronic granulomatous diseases (Johne’s disease and TB)
-Age related arterosclerosis
-Aortic lesions associated with migrating larvae of Spirocerca lupi in dogs
Arterial calcification
Fibrinoid necrosis
-describes vascular change in small arteries and arterioles characterized by deposition of acidophilic proteinaceous material in vascular walls
Conditions causing fibrinoid necrosis
-viral infections (swine fever, porcine circovirus)
-toxic conditions (uremia, mercury poisoning)
-bacterial toxins (enterotoxemia and edema disease of swine (E.coli))
-Nutritional deficiencies (mulberry heart disease)
-Purpura hemorrhagica in horses from Streptococcus equi infections
-immune mediated vasculitis (lupus)
Fibrinoid Necrosis
Vasculitis
-inflammation of small arteries and veins
-only detectable by histopathology but its effect is seen grossly as hemorrhage, edema, small infarcts
Common causes of vasculitis
-systemic infections
-hypersensitivities where antigen-antibody complexes attach to walls of blood vessels
-adverse drug reactions
Signs of Vasculitis
-edema
-meningoencephalitis
-infarction and hemorrhage in omasum
Arteritis
-mesenteric artery in a horse
-linked with Strongylys vulgaris and colic
Dirofilaria immitis
Adult nematodes parasitize the right ventricle and pulmonary arteries
*can cause endoarteritis
Dirofilaria immitis
Phlebitis
Inflammation of the veins
-often become thrombosed, resulting in thrombophlebitis
Common forms of thrombophlebitis
- Vena cava thrombosis
-cattle; secondary to hepatic abscess eroding wall of vena cava - Omphalophlebitis
-umbilical veins become infected and inflamed after birth
3.Latrogenic phlebitis
-improper venipuncture
4.Parasitic phlebitis
-eg. Schistosoma sp. (blood fluke trematode)
Vena Cava thrombophlebitis
-can lead to thrombus detaching and becoming embolic pneumonia
-Omphalophlebitis
Thrombosis and Thromboembolism
-occur from vascular or endocardial diseases or coagulopathies
-Horses: Strongylus vulgaris
-Dogs: primary cardiomyopathies, Dirofilaria immitis
-Cats: primary cardiomyopathies
-Cattle: Valvular endocarditis, septicemia, vena cava thrombosis
-Pigs: valvulr endocarditis
Lymphangiectasia
-abnormal dilation of lymphatic vessels
*intestinal lymphangiectasia is common cause of protein losing enteropathy in dogs
Lymphangiectasia
-dog
-dilated mesentery
Chylothorax and Chyloabdomen
-rupture of lymphatics and leakage of chyle into thoracic or abdominal cavities
-causes: trauma, idiopathic, surgery, inflammation, neoplasia
Chylothorax
Lymphagitis
-inflammation of lymphatic vessels
-seen with Johne’s disease (mycobacterium avium subsp paratuberculosis)
- Glanders (Burkholderia mallei),
- Ulcerative lymphagitis (Corynebacterium pseudotuberculosis)
-Epizootic lymphangitis
-Sporotrichosis
