Pathophysiology Flashcards
What do lipoproteins do?
Carry lipids
What are chylomicrons?
Carry fat from the gut to the liver
What are VLDL and what are the subtypes?
Very low density lipoproteins. They are made from the fat by the liver and there are two types
IDL - intermediate density - also bad
LDL - Bad lipoproteins - carry cholesterol to the body and settles in vessels
What are HDLs?
High density lipoproteins
good fats - take cholesterol back to the liver
What is familial hypercholesteramia?
Elevated cholesteral. Normal levels are<5
What is hyperlipidaemia?
Elevated levels of lipids in the body
Increased chylomicrons or LDL
Decreased HDL
How do statins work?
Stop the formation of cholesterol by inhibiting mevalonate
Why do high lipid levels matter?
They collect in atheromatous plaques which can lead to thrombus formation
What are some risk factors for heart disease?
- DM
- Hypertension
- Obesity
- Smoking
- Alcohol
- FH
- Male
- High cholesterol
What are the layers of arteries called and what do they do?
Intima - Endothelium and elastic lamina
Media - Muscle
Adventitia - Blood supply and nerve
What is the key process in the formation of atheromatous plaques?
Endothelial stress and activation and accumulation of lipds
What do the plaques contain?
Macrophages, collagen, lipids, smooth muscle cells and the formation of new blood vessels
What protects plaque stability?
Smooth muscles cells
NO
Why does a thrombus occur?
When the plaque ruptures releasing the contents and activation the coagulation cascade. This causes infarction
What increases the instability of a plaque?
High lipids
Low Smooth muscle cells
high metalloproteinases
High levels of neovasculargenesis
High macrophage density
Why may an MI occur without previous chest pain?
You could have a small unstable plaque. This would mean minimal ischaemia and chest pain but once it ruptures, an MI would occur
