Pathogenesis of Atherosclerosis Flashcards
What is the definition of atherosclerosis?
Hardening of the arteries
In what size vessels does atherosclerosis occur?
Large and medium size muscular arteries
In what layer of the vessel does atherosclerosis begin?
Intima
Is coronary artery disease symptomatic or asymptomatic?
Asymptomatic
What are clinical manifestations of coronary artery disease?
Chronic stable angina
Acute coronary syndrome
Sudden death
Congestive heart failure
What is the key event in the pathogenesis of atherosclerosis?
Focal accumulation of lipid and cells beneath the endothelium
What are the 3 pathologic manifestations of atherosclerosis?
Fatty streak
Fibrous plaque
Complications of plaque
What is the fatty streak and when does it appear?
Area of yellow discoloration on inner surface of artery, does not impede blood flow
Earliest visible lesion of atherosclerosis
When does the fibrous plaque appear?
More advanced lesion
Can project into lumen and may limit blood flow
What are complications related to a plaque?
Rupture or ulceration of the plaque (can cause thrombosis) Weakening of vessel wall Hemorrhage Embolization Calcification of plaque
What antithrombotic and antivasoconstrictive substances are released by the endothelium?
Nitric oxide
Prostacyclin
Bradykinin
What thrombotic and vasconstrictive substances are released by the the endohelium?
Endothelin
Angiotensin II
Norepinephrine
What are 4 functions of normal endothelium?
Barrier function
Antithrombotic activity
Promotes vasodilation
Inhibits smooth muscle migration and proliferation of lipid below endothelium
What happens to the normal functions of endothelium when it gets disrupted?
Endothelium becomes permeable
Lose antithrombotic activity
Reduced vasodilation
Promotes smooth muscle migration
What are the steps of foam cell formation?
LDL enters intima
LDL gets oxidized
Oxidized LDL induces cytokines, which cause increase in adhesion molecules on endothelium
Macrophages attach to endothelium and migrate into intima
Macrophages take up oxidized LDL –> FOAM CELL
Accumulation of foam cells = fatty streak