Lecture 26 - Atherosclerosis Flashcards
lipids, such as cholesterol and triglycerides, are _____ in plasma
insoluble
due to their insolubility in plasma, lipids must be transported in association with:
proteins (lipoproteins)
what are the five main types of lipoproteins?
- chylomicrons
- VLDL (very low density lipoprotein)
- IDL (intermediate density lipoprotein)
- LDL (low density lipoprotein)
- HDL (high density lipoprotein)
produces by the intestine from dietary lipids; these lipoproteins are involved in the transport of dietary triglycerides (TG) and cholesterol to hte peripheral tissues and liver
chylomicrons
lipoproteins which are produced by the liver and carry lipids (many TGs) from the liver to the tissues
very low density lipoprotein (VLDL)
a VLDL remnant; the removal of TG from VLDL by muscle and adipose tissue results in the formation of these particles
intermediate density lipoprotein (IDL)
these particles are derived from VLDL and IDL, and carries the majority of the cholesterol that is in the circulation
low density lipoprotein (LDL)
plays an important role in reverse cholesterol transport from the peripheral tissues to the liver –> removes excess cholesterol from the cells and tissues
high density lipoprotein (HDL)
what are lipoproteins?
packages of lipids (triglcerides, cholesterol) surrounded by apolipoproteins and phospholipids
lipoproteins are categorized according to:
size and presence of specific apolipoproteins
an inappropriate balance of lipoproteins is a risk factor for:
serious diseases
the amount of lipid present within a lipoprotein determines its:
density
if lipoprotein density is low, it is made of more ____ than ____
lipid, protein
list the major steps of the cholesterol biosynthesis pathways
acteyl CoA + acetoacetyl CoA –HMG-CoA reductase–> HMG-CoA –> mevalonate –> geranyl pyrophosphate –> farnesyl pyrophosphate –> cholesterol
high levels of total cholesterol (especially LDL-C) are linked to:
adverse cardiovascular events
high levels of total cholesterol is attributed to the formation of:
atherosclerotic plaques
what are the two leading causes of death in the world?
rupture of atherosclerotic plaques followed by occlusion of vessels in the heart or brain
elevated ____ is linked with reduced chances of atherosclerosis
high density lipoprotein (HDL)
the major anti-atherosclerotic effect of HDL is felt to be:
reverse cholesterol transport
what are five major effects of high HDL?
- improved endothelial function
- anti-apoptosis
- anti-inflammation
- anti-oxidation
- stimulated macrophage cholesterol efflux
a disease that is characterized by the accumulation of lipids in the blood which form plaques in the walls of large and medium sized arteries
atherosclerosis
a atherosclerotic plaques build up, the arteries become _____. this reduces the supply of _____ to the tissues and organs leading to _____
narrower, oxygen-rich blood, tissue ischemia (limited blood flow)
list the four major steps to the development of an atherosclerotic plaque
1) dysfunction of endothelial cells leads to migration of LDL, resulting in the expression of monocytes on the endothelial cells and inflammation
2) monocytes transmigrate to the intima and differentiate into macrophages, binding to oxidized LDL, which causes the formation of foam cells
3) inflammation drives smooth muscle cell migration with collagen, forming a fibrous cap
4) plaque accumulation and inflammation thin the fibrous cap, leading to rupture and throumbus formation
review slide 787
good way to brush up on plaque formation
