Vascular System Flashcards
What is the vascular system formed by ?
- arteries (elastic & muscular)
- arterioles (microscopic)
- capillaries (microscopic)
- venules (microscopic)
- veins
what other vessels are also considered part of vascular system?
lymphatic
microcirculation or systemic capillary bed is formed by ?
arterioles, capillaries, & venules
Where does actual exchange between blood and tissue take place?
capillaries
What can vascular lesions cause?
Edema, hemorrhage, thrombosis, ischemia, & infarction in affected tissues & organs
5 degenerative diseases of arteries?
- Arteriosclerosis
- Atherosclerosis
- Arterial hypertrophy
- Aneurysms
- Arterial medial calcification
Arteriosclerosis vs atherosclerosis?
They are distinct degenerative diseases of arteries that are manifested by hardening of arterial wall, loss of elasticity, & in many cases, reduced vascular lumen. In Atherosclerosis, lesions predispose to arterial rupture
What degenerative disease of arteries other than Atherosclerosis also predisposes to arterial rupture?
Aneurysms
what does artiosclerosis mean etymologically?
hardening of an artery
What is arteriosclerosis?
degenerative change w/ loss of arterial elasticity, hardening, & luminal narrowing
Where is arteriosclerosis mainly found?
elastic arteries (abd aorta); arterial branching sites are commonly affected
gross appearance of arteriosclerosis?
intima has raised corrugated wht plaques (multiple coalescing areas of intimal thickening) while normal vessel has smooth surface
what do arteriosclerosis plaques consist of ?
fibrous tissue & smooth muscle proliferation, sometimes mineralization
What is atherosclerosis?
major cause of mortality in humans in which excessive circulating cholesterol is deposited in arterial walls
how common is atherosclerosis in domestic animals?
comparatively rare compared to humans
What does atherosclerosis lead to in humans?
acute myocardial infarction (heart attack); (prevalent in humans, relatively rare in domestic animals)
major risk factors of atherosclerosis in humans?
- familial hypercholesterolemia
- high blood press
- poor diet habit (ex: junk food)
- sedentary life-style
- cigarette smoke
What are atheromas?
cholesterol plaques in intima & media of arteries
Where are atheromas particularly common?
coronary arteries (heart attacks) & in cerebral arteries (stroke)
Where is atherosclerosis most commonly reported in domestic spp?
hypothyroid dogs w/ hypercholesterolemia or diabetes mellitus; Sw, psittacine birds, & pigeons fed high lipid diet
steps in formation of atheromas?
- early cholesterol deposits in intima
- accumulation of cholesterol & lipid-laden macrophages in arterial wall
- large lipid plaques (atheromas) occlude arterial lumen & cause ischemia
Gross appearance of atherosclerosis?
prominent thick arteries
histo appearance of atherosclerosis?
atheromatous plaques contain foamy, lipid-laden macrophages, cholesterol clefts, fibroblasts, & smooth muscle proliferation
Describe atherosclerosis in lovebird? (gross)
hx of progressive weight loss; on post mortem, mjr arteries were hard & rigid
Describe atherosclerosis in lovebird? (histo)
lipid laden macrophages in arterial wall; lumen of medium sized artery is markedly occluded
what is arterial hypertrophy?
another arterial change that occurs in muscular arteries; characterized by hypertrophy & hyperplasia of smooth muscle which results in loss of elasticity, narrowing of arterial lumen, & increased resistance
what is common cause of arterial hypertrophy?
hypertension
Describe arterial hypertrophy with brisket disease:
high altitude -> pulmonary hypertension -> medial hypertrophy of pulmonary arteries -> increase flow resistance -> dilation/hypertrophy of R ventricle -> R heart failure -> ascites & sub Q edema
histo appearance of pulmonary artery with brisket disease?
moderate hypertrophy of smooth muscle
history of arterial hypertrophy & pulmonary hypertension in Fe?
- muscular hypertrophy is frequently seen in lungs of Fe
- in past this change was associated w/ Aelurostrongylus abstrusus (feline lungworm), but this idea has been abandoned since identical lesions have been found in Specific Pathogen
Dirofilaria immitis (dog heartworm) in cats can cause?
both smooth muscle hypertrophy & intimal proliferation/inflammation (endoarteritis)
hypertension & medial hypertrophy in cats can also be caused by which disease?
renal disease
histo appearance of arterial hypertrophy in cats?
severe hypertrophy of smooth muscle, intimal proliferation, & narrowing of vascular lumen