athlerosclerosis Flashcards
why is atherosclerosis more common in men than women
because of the protective effect of oestrogen
what is atherosclerosis initiated by
endothelial injury or dysfunction
where to plaques tend to develop
areas of variable haemodynamic sheer stress eg where arteries branch or bifurcate
what does endothelial dysfunction cause
adhesion of monocytes, which become macrophages
what do macrophages do
act as scavenger cells to remove dead cells and foreign material
and release cytokines and GF to promote healing
what happens to LDL
oxidised by oxidants derived from macrophages and endothelial and SM cells
what does OXLDL do
attracts circulating monocytes and inc expression of endothelial cell adhesion molecules to which monocytes attach
what do monocytes then do
penetrate the endothelial monolayer and form macrophages
what happens when macrophages accumulate lots of OXLDL
become cholesterol laden foam cells
what do foam cells form
fatty streak
what does stimulation of macrophages and endothelial cells by OXLDL cause them to release
cytokines
wat do cytokines do
act on the SM of the cells of the media causing them to migrate into the intima, proliferate and secrete lots of collagen and connective tissue proteins
what does the accumulation of SM cells and connective tissue proteins cause
fibrous cap on inner arterial wall
what happens under the fibrous cap
foam cell deterioration and release lipids
and cellular debris
what is the fibrous cap formed of
SM and connective tissue
