atherosclerosis Flashcards
(15 cards)
arteriosclerosis
thickening and loss of elasticity of arterial walls
3 patterns of arteriosclerosis
1 - Monkeberg medial calcific sclerosis - deposits in muscular arteries in persons over 50 that do not encroach the vessel lumen
2 - arteriolosclerosis - small arteries and arterioles with narrowing of lumen and potential downstream ischemia
3 - atherosclerosis - large arteries, localized thickening of the wall with lumen narrowing
3 consequences of atherosclerosis
1 - lesions mechanically obstruct blood flow
2 - lesions rupture, leading to emboli and thrombosis
3 - plaques weaken the underlying media and lead to aneurysms
foam cells
monocytes that have taken up lipids from lipoprotein particles
fatty streak
collection of foam cells in the intima
atheroma features
- intimal thickening
- lipid accumulation
- raised focal lesions
- obstruction of lumen
- weaken tunica media underneath
- covered by endothelium or fibrous cap
fibroatheroma
atheroma plus production of collagen creating a fibrofatty plaques
complicated plaques
- the stage at which clinical manifestations appear
- calcification, ulceration, thrombosis, hemorrhage into plaque
clinical complications of atherosclerosis are due to:
plaque rupture
major targets of atherosclerosis
- large elastic arteries (aorta, carotid, iliac)
- large and medium sized muscular arteries (coronary and popliteal)
symptomatic atherosclerotic disease most often involves there arteries supplying:
heart, brain, kidneys, lower extremities
major consequences of atherosclerosis
- MI
- Cerebral infarction (stroke)
- aortic aneurysms
- peripheral vascular disease
3 clinical phases involving advanced vulnerable plaque
1 - aneurysm and rupture - vessel wall opens to exterior environment
2 - occlusion by thrombus - after plaque rupture
3 - critical stenosis - plaque continues to grow until it occludes lumen
epithelial injury hypothesis
- atherosclerosis is a chronic inflammatory response of the arterial wall initiated by injury to epithelium
- injury —-> dysfunction ——> atherosclerosis
5 steps in pathogenesis of atherosclerosis
1 - chronic endothelial injury (hyperlipidemia, hypertension, smoking, toxins, viruses, immune reactions, etc.)
2 - endothelial cell dysfunction (increased permeability, leukocyte and monocyte adhesion and emigration)
3 - migration of smooth muscle cells into the intima
4 - monocytes/macrophages/SM cells engulf lipids and become foam cells
5 - smooth muscle proliferation and collagen deposition
