what is affected in atherosclerosis?
Arteries, NOT veins
response-to-injury-hypothesis
atherosclerosis is a chronic inflammatory & healing response of the arterial wall to endothelial damage. Lesion progression occurs through interaction of modified lipoproteins, macrophages & T-cells with the normal cellular components of the arterial wall.
atherosclerotic pathogenic events
- Endothelial injury (increased permeability)
- LDL accumulation
- monocyte adhesion->macrophages-> foam cells
- platelet adhesion
- recruiting factors released
- SMC proliferation & ECM production
- extra, intracellular accumulation of lipids
media is composed of:
smooth muscle cells
adventitia is composed of:
blood vessels (Vasoasum)
SMCs can go from media to ____ during inflammation
intima
in media, SMC
can not divide & do not produce ECM proteins
- only contract & relax
scavenger receptors for modified lipoproteins & other receptors for
oxidized LDL & VLDL
major components of atheromas
fibrous cap
core
atheroma acute changes
- rupture or fissuring
- erosion & ulceration
- hemorrhage into atheroma
thrombotic occlusion in coronary artery is the most common cause of
MIs
calcification
mineralization of the atherosclerotic plaauq recapitulates many aspects of bone formation
- stiff arteries; cannot respond to changes in BP
atherosclerosis manifestation
- no symptoms
- compensatory enlargement
- stenotic occlusive disease
- ectasia, aneurysm
- thrombosis
- rupture
intermittent claudication
- pain in calf when exercising
- arteries become narrowed & blood flow decreases in atherosclerosis
atherosclerosis in coronary arteries
->MI and angina pectoris
atherosclerosis in CNS
-> stroke, encephalopathy
atherosclerosis in peripheral circulation
->intermittent claudication & gangrene
atherosclerosis in splanchnic circulation
->mesenteric ischemia
atherosclerosis in kidneys
->renal artery stenosis
MI
- pain in the chest radiating up to the jaw or down the left, or less often, right arm might signal a heart attack
- necrosis of part of the heart
angina pectoris
insufficient blood flow to the heart muscle from narrowing of coronary artery may cause chest pain.
mesenteric ischemia
ischemia of intestines->necrosis
preferred sites of atherosclerosis
- proximal left descending coronary artery
- proximal portions of renal arteries
- extracranial circulation of the brain
- the carotid bifurcation
- branching points of arteries
- abdominal aorta (posterior wall)
- due to blood flow alterations (turbulent flow)
what is the major cause of death & premature disability in developed societies?
atherosclerosis
