Atherosclerosis Flashcards
What characterizes normal endothelial cells?
Smooth with very tight junctions between individual cells
Name two factors that can cause endothelial injury.
- Cigarette smoking
- Mechanical stress caused by hypertension
Where do atherosclerotic lesions tend to form?
Where vessels branch or in areas of turbulent flow
What happens to monocytes in response to endothelial injury or high LDL levels?
They become sticky and attach to the endothelium
What is lost when the endothelium suffers injury?
Its ability to produce antithrombotic and vasodilating cytokines
What occurs to monocytes after they migrate into the intimal layer?
They transform into macrophages and release free radicals
What do macrophages consume that leads to foam cell formation?
Oxidized LDLs
What effect do foam cells have on endothelial injury?
They release growth factors and inflammatory cytokines that worsen the injury
What type of lipoproteins are quickly oxidized into proinflammatory lipids?
Low density lipoproteins (LDLs)
What is the consequence of LDL oxidation in the context of atherosclerosis?
It serves as an attractant for further monocyte migration
What happens when platelets are exposed to the subendothelium?
They aggregate and adhere to the site of injury
What is the result of smooth muscle proliferation in the context of atherosclerosis?
The endothelial layer pouches out, making the lumen of the vessel smaller
What are fatty streaks, and what do they consist of?
Thick, flat, yellowish discolorations consisting of macrophages and smooth muscle cells distended with lipid
What forms as lipids accumulate beneath the endothelial layer?
A hard, lipid core
What happens to the fibrous cap of an atherosclerotic plaque?
It can be eaten away by enzymes, making the plaque vulnerable to rupture
What is released when a plaque begins to fissure or rupture?
Prothrombogenic mediators
What is the consequence of thrombus formation in the coronary artery?
Blood flow can be compromised or completely obstructed, leading to infarction
Fill in the blank: The process leading to plaque rupture and hemorrhage in atherosclerosis is called _______.
atherogenesis
