Atherosclerosis

Question 1

where does atherosclerosis usually occur and why

Answer 1

arteries
high pressure blood can damage artery endothelium
narrow lumen means it can become blocked easily

Question 2

what is the process of atherosclerosis

Answer 2

damage to endothelium (high pressure)

inflammatory response

white blood cells gather at damaged wall

build up of cholesterol, calcium salts and fibrous tissue (blood clotting cascade) sticks to endothelium

fatty build up causes atheroma and plaque

plaque hardens and artery wall becomes less elastic

self perpetuating (positive feedback) keeps occurring

Question 3

why is atherosclerosis an example of positive feedback

Answer 3

arteries lumen narrows due to plaque
blood pressure increases
can cause other arteries to become damaged

Question 4

what happens if an artery becomes fully blocked

Answer 4

lack of oxygen to cells
cells begin to respire anaerobically
lactic acid builds up causing pain
cells die

Question 5

what are the consequences of atherosclerosis

Answer 5

angina- narrowing of coronary arteries causes chest pains as cardiac muscle lacks oxygen
coronary heart disease- if collagen is exposed clotting cascade happens. Blood supply to heart can become blocked causing heart attacks
stroke- blood supply to brain is cut off (by blood clots) brain cells will be starved of oxygen and could lead to permanent damage or death
aneurysms- if artery is blocked blood can form behind blockage causing a bulge (could burst)

Question 6

what are the risk factors of atherosclerosis

Answer 6

high blood pressure
high cholesterol