Atherosclerosis Flashcards
3 layers of the artery
Intima, Media, Externa
2 parts of the tunica intima
Endothelium and Elastic membrane
Inner lining of tunica intima
Endothelium - Clot resistant!!
Tunica media
Smooth muscle that constricts and dilates
Tunica externa
Adventitia that holds arteries in place
5 Steps of atherosclerosis
Fatty Streak
Fibrous Cap
Disruption of vasa vasorum (neovascularization)
Fibrous plaque
Intraplaque hemorrhage
Foam cells
Macrophages that have eaten lots of LDL
Form fatty streak
Smooth muscle migrates to the site
Vasa vasorum disruption
Blood flow created to fatty streak making it grow
Fibrous cap
Collagen layed down over streak - more collagen=more stable
Fibrous plaque
Smooth muscle cells take up LDL and make the clot more stable
Positive remodeling
Increased vessel size d/t plaque making it UNSTABLE
Negative remodeling
Body constricts the vessel to stabilize plaque - STABLE angina
Interplaque hemorrhage
Critical event - Leads to an MI
2 things needed for atherosclerosis
Lipids and Inflammation
Four endothelial trauma etiologies with common mechanism
Turbulent blood flow - HTN
Diabetes
HLD
Cigarette smoking
Occurs due to loss of endothelial-derived nitric oxide