Sub 3: Cardiovascular Disease Flashcards
what are lipoproteins?
small bags made up of a layer of phospholipid with some proteins floating in the layer
what is the function of lipoproteins?
necessary for the transport of hydrophobic lipid molecules in the bloodstream.
what is atherosclerosis?
when artery is injured, low density lipoproteins (LDLs) add cholesterol to the cells under the endothelial lining of the artery
phagocytic cells move under the lining to remove the cholesterol
phagocytic cells turn into foam cells which accumulate
fibroblast cells move under the lining and deposit a fibrous material over the foam cells, fibrous material builds up and gradual build up of calcium forms plaque
as plaque builds up, lumen of artery becomes narrower, restricting blood flow.
what is hypertension?
persistent high blood pressure
how is hypertension a cause of atherosclerosis?
long periods of high blood pressure can cause the initial injury to the arterial wall that allows the atherosclerosis to start
what is angina pectoris?
when atherosclerosis occurs in the coronary arteries, narrowing due to plaque restricts blood flow to the myocardium.
cardiac muscle cells do not receive enough oxygen to maintain aerobic respiration - so causing anaerobic respiration felt as an extreme chest pain
what is thrombosis?
atherosclerosis plaque makes the inner surface of the artery rough
platelets can attach to this rough surface and then start to release clotting factors
this leads to a thrombus (blood clot) in the artery
if thrombus blocks the artery, thrombosis occurs cutting off blood supply
what is an embolism?
when a thrombus starts to build up, increased blood pressure may break off part of the clot
free-floating clot is called an embolus an it is moved along the artery until it blocks a smaller part of the circulatory system. blockage is called an embolism
what is a myocardial infarction (heart attack)?
caused by thrombosis or an embolism in the coronary artery
what is a cerebral infarction (stroke)?
thrombosis or embolism in the brain artery
what are non-modifiable risk factors of CVD?
age, gender - males have more LDLs in blood
hereditary, race
what are modifiable risk factors of CVD?
diet - high fat diet means more LDLs in blood, smoking, obesity, inactivity
what are the benefits of exercise?
myocardial circulation is improved by development of denser capillary networks
increasing thickness of the muscle fibre
