module 12-13 Flashcards
(170 cards)
What is coronary heart disease?
- when coronary blood circulation fails to adequately supply the heart with blood
What is the primary cause of coronary heart disease?
athlerosclerosis
what is athlerosclerosis?
when plaques build up on the walls of the arteries, causing the artery to narrow, resulting in decreased blood flow to the heart
what is the relation between coronary heart disease and cholesterol levels?
people with high blood cholesterol are at risk of developing coronary heart disease
Cholesterol’s role in the body (3)
- cell membranes
- precursor of steriod hormones
- precursor of bile salts
where does cholesterol come from? (2)
- diet (exogenous)
- through synthesis (endogenous)
what percent of body’s cholesterol is endogenous vs exogenous
- endogenous = 80%
- exogenous = 20%
Lipoproteins - structure
- outer hydrophillic shell = phospholipids
- core = lipophilic cholesterol and triglycerides
- Apolipoproteins - embeded in phospholipid shell
Lipoproteins - function
transport cholesterol and triglycerides in the blood (since both are lipophilic, they cannot disolve in blood otherwise)
Apoplipoproteins function (3)
1) allow recognition by cells which may bind and ingest lipoproteins
2) activate enzymes that metabolize lipoproteins
3) increase the structural stability of lipoproteins
Lipoproteins with apoplipoprotein AI - function
transport cholesterol from non-hepatic tissue back to the liver
lipoproteins that contain apoplipoprotein B-100
transport cholesterol to non-hepatic tissue
how do we classify lipoproteins
based on density
very-low density lipoproteins, low density lipoproteins, high density lipoproteins
Very low density lipoproteins - function
- deliver triglycerides from the liver to adipose tissue and muscle
Very low density lipoproteins - core composition
very rich in triglycerides
Very low density lipoproteins - athlerosclerosis
- some studies show link to atherosclerosis
Very low density lipoproteins - apoplipoprotein
contain apoplipoprotein B-100, which allows them to bind to cells and transfer their lipid to cells
Low density lipoproteins - function
deliver cholesterol to non-hepatic tissue
Low density lipoproteins - core composition
- cholesterol rich core = 60-70% of cholesterol in blood
Low density lipoproteins - apoplipoprotein
- apoplipoprotein B-100 - which allows them to bin to cells and transfer their lipid to cells
Low density lipoproteins - athelosclerosis
- clear link between LDL cholesterol adn development of atherosclerosis
- higher the blood LDL level, the greater the risk of developing coronary heart disease
- reducing blood LDL levels halts or even reverses atherosclerosis and has ben proven to decrease death from coronary heart disease
- AKA “bad cholesterol”
High density lipoproteins - function
deliver cholesterol from non-hepatic tissue back to the liver. Promote cholesterol removal from the blood.
- aka the “good cholesterol”
High density lipoproteins - core composition
have cholesterol as their main core lipid and account for 20-30% of total blood cholesterol
High density lipoproteins - and coronary heart disease
elevated HDL decreases risk of coronary heart disease