pathology of cardiovascular disease 2.7

Question 1

cardiovascular diseases

Answer 1

diseases of the heart and it’s associated blood vessels

Question 2

main types of cardiovascular diseases

Answer 2

coronary heart disease, heart attacks, strokes, angina and peripheral vascular disorders

Question 3

atherosclerosis

Answer 3

the accumulation of fatty materials forming an atheroma or plaque beneath the endothelium of an artery

Question 4

what problems can an atheroma cause

Answer 4

artery thickens and loses elasticity, diameter of the lumen is reduced and blood flow is restricted resulting in increased blood pressure

Question 5

thrombosis

Answer 5

• at the site of an injury, blood clotting factors are released to clot blood and prevent blood loss
• atheroma may rupture and damage the endothelium
• this damage causes the release of clotting factors that activate a cascade of reactions resulting in the conversion of the enzyme prothrombin to its active form thrombin
• thrombin causes molecules of plasma protein fibrinogen to form threads of fibrin
• the fibrin threads form a mesh work that clots the blood, seals the wound and provides a scaffold for the formation of scar tissue
• the formation of a clot (thrombus) is referred to as thrombosis

Question 6

embolus

Answer 6

-in some cases a thrombus may break loose forming an embolus which travels through the bloodstream until a blood vessel is blocked
- a blocked blood vessel means cells become deprived of oxygen which leads to death of tissues
- thrombosis in a coronary artery may lead to a myocardial infarction commonly known as a heart attack
- a thrombosis in an artery in the brain may lead to a stroke

Question 7

peripheral arteries

Answer 7

arteries other than those of the heart and brain

Question 8

peripheral vascular disease

Answer 8

narrowing of peripheral arteries due to atherosclerosis

Question 9

deep vein thrombosis

Answer 9

• a blood clot that forms in a deep vein and most commonly in the legs due to lack of movement
• pain and swelling are experienced due to a limited supply of oxygen

Question 10

pulmonary embolism

Answer 10

• when an embolus blocks the pulmonary artery in the lungs
• symptoms include chest pains, breathing difficulties and palpitations

Question 11

cholesterol

Answer 11

a type of lipid found in the cell membrane

Question 12

use of cholesterol

Answer 12

make the sex hormones

Question 13

what increases cholesterol levels in the blood

Answer 13

high diet of saturated fats and salts

Question 14

lipoproteins

Answer 14

to transport lipid from one part of the body to another

Question 15

high density lipoprotein

Answer 15

• transports excess cholesterol from the body cells to the liver for elimination
• this prevents the accumulation of cholesterol in the blood
• HDL cholesterol isn’t taken into artery walls so doesn’t contribute to atherosclerosis

Question 16

low density lipoprotein

Answer 16

• transports cholesterol to body cells
• most cells have LDL receptors on their cell membrane that take LDL cholesterol into the cell where it releases its cholesterol for use by the cell

Question 17

negative feedback control

Answer 17

• once a cell has sufficient cholesterol a negative feedback system inhibits the synthesis of new LDL receptors and LDL cholesterol circulates in the blood where it may deposit cholesterol in the arteries forming atheromas
• a higher ratio of HDL to LDL will result in lower blood cholesterol and reduced chance of atherosclerosis and CVD

Question 18

reducing cholesterol levels

Answer 18

regular physical activity, reduce levels of total fat in diet and drugs such a statins