Atherosclerosis Flashcards
what types of blood vessels does atherosclerosis effect
elastic and medium to large muscular arteries
what are the two aspects of an atheroma
- intimal fibrous cap
- central core rich in lipids
why has the number of deaths related to atherosclerosis
- prevention of atherosclerosis
- improved methods of treatment
- prevention of recurrences
what are the biggest risk factors of atherosclerosis
age (older generations)
sex (men) (although women once they reach menopause)
genetics (family inherited)
hyperlipidaemia (High low density cholesterol levels)
hypertension
smoking
diabetes mellitus
what are the three stages of pathogenesis
initiation/formaiton stage (subclinical) adaption stage (subclinical) clinical stage (complications)
what results from a chronic endothelial injury and what are some causes
- smoking
- toxins
- immune reactions
- hypercholesterolemia
Macrophage cells break through the lumen and migrate into the tunica intima
ENDOTHELIAL DYSFUNCTION = leukocyte/monocyte adhesion, increased permeability and emigration
what results from hyperlipidaemia (LDL cholesterol)
impairs endothelial function
accumulates within intima
causes oxidative modification of LDL
what is the process of oxidation of LDL cholesterol
they are injected by macrophages via scavenger receptors = becoming foam cells
this effects the motility of macrophages and stimulates the release of cytokines
CYTOTOXIC TO ENDOTHELIAL AND SMOOTH MUSCLE CELLS
Why does eating fruit and veg lower the chances of developing atherosclerosis
they contain antioxidants which prevent oxidation of LDLs so they are never eaten
monocyte
macrophage in the blood
once the formation of foam cells has taken place what occurs in the tunica intima
there is smooth muscle migration from the tunica media to the intima, this also causes activation of the macrophages. this means that the smooth muscle and macrophages begin to engulf lipids, raising the lumen to show a FATTY STREAK
What happens after the formation of the fatty streak
smooth muscle proliferation begins as it migrates to encompass the atheroma to the surface of the plaque.
this causes collagen and ECM deposition.
it goes from a fatty streak to a mature fibrofatty atheroma
what makes up the fibrous cap
smooth muscle cells, macrophages, foam cells, lymphocytes, collagen, elastics, prosteoglycans and neovascularisation
what makes up the necrotic centre
cell debris, cholesterol crystals, foam cells and calcium
where are you most likely to see the formation of atheromas
abdominal aorta coronary artiers popliteal arteries descending thoracic aorta internal carotid artiers vessels of the circle of willis
