Biology Topic 1A Key Questions

Why does high blood pressure increase the risk of developing CVD?

• M1: High blood pressure causes damage to the lining of the endothelium of the arteries

• M2: Inflammatory response/ build up of cholesterol leads to the formation of atheroma

• M3: plaque develops and narrows the lumen of the artery

Describe how very high blood pressure could result in atherosclerosis?

• M1: High blood pressure damages the endothelium of the artery

• M2: causing an inflammatory response

• M3: {white blood cells/cholesterol} accumulate/ atheroma forms

• M4: Calcium salts and fibrous tissue build up/ formation of a plaque

Explain why does a whole between the two ventricles make a person feel tired very easily due to lack of energy? (3)

• M1: less oxygen available for aerobic respiration

• M2: deoxygenated blood mixes with oxygenated blood

• M3: Therefore, reducing the concentration of oxygen in the blood circulating in the body

• M4: Because some deoxygenated blood does not leave right ventricle/ is transferred to the left ventricle/ does not leave the lungs/ goes to the respiring tissues

Explain how the diet of a person coulf affect the development of CVD? (4)

• M1: High salt intake

• M2: increases blood pressure

• M3: High blood pressure causes damage to the endothelium of artery

• M4: high intake of {cholesterol/ saturated fat)

• M5: High {LDL’s/saturated fat} linked to {atheroma/plaque formation)

Describe the role of LDL in the development of atherosclerosis

• M1: LDL carry cholesterol in the blood

• M2: Cholesterol is deposited to form atheroma

• M3: in the endothelium of an artery (artery wall)

Explain how atherosclerosis can result in damage to heart muscle? (3)

• M1: Atherosclerosis narrows the lumen of the coronary artery

• M2: Which reduces {blood flow/oxygen} to the cardiac muscle

• M3: Which reduces aerobic respiration

Describe the role of thrombin in blood clotting. (3)

• M1: Thrombin is an enzyme

• M2: Which catalyses the conversion of fibrinogen into fibrin

• M3: A mesh of fibrin traps {platelets/ red blood cells} to form a clot

Explain why a blood clot in the large artery in the lungs would greatly affect the oxygen saturation of the blood leaving the lungs? (3)

• M1: Decrease in oxygen saturation as it would result in reduced blood flow in the lungs

• M2: This would result in reduced gas exchange

• M3: Therefore, fewer red blood cells can be oxygenated

Explain how a blood clot could form in a blood vessel? (4)

• M1: collagen is exposed when wall of the blood vessel is damaged

• M2: leading to release of thromboplastin

• M3: thromboplastin catalyses the conversion of prothrombin to thrombin

• M4: Thrombin catalyses the conversion of fibrinogen to fibrin

• M5: Fibrin forms a mesh of fibres and traps red blood cells to form a clot

Explain the role of antihypertensive drugs in reducing the risk of atherosclerosis. (4)

• M1:Antihypertensive drugs lower blood pressure

• M2: Lower blood pressure reduced risk of damage to endothelium of the artery

• M3: Reduces risk of inflammatory response

• M4: reduces risk of {atheroma/plaque} formation

Describe how high blood pressure could be reduced by medication and lifestyle changes? (3)

• M1: Treatment with antihypertensive medication

• M2: Reduce salt intake

• M3: Stop smoking

• M4: Increase exercise

• M5: Reduce weight

Explain the effect that a diet high in salt could have on a person’s risk of developing cardiovascular disease?

• M1: High diet in salt increases risk of CVD

• M2: High salt intake causes high blood pressure

• M3: Which increases risk of {damage to endothelium of artery/atherosclerosis}

• M4: Therefore, increases risk of inflammatory response

• M5: Leading to increased risk of {atheroma/plaque formation}

• M6: narrowing of arteries {increases risk of blood clots/ increases blood pressure/ reduces blood flow to the cardiac muscle}

Devise a procedure to compare the effects of decaffeinated coffee and regular coffee on the heart rate of Daphnia. (4)

• M1: detail of the procedure (use of a microscope/ method of counting/ allowing acclimatisation)

• M2: record the heartbeat before and after placing in regular or decaffeinated coffee

• M3: control variable for coffee (concentration or volume)

• M4: control temperature/ length of time to count heartbeat/ same species

• M5: use a suitable statistical test to compare the results (standard deviations)

Explain how pressure differences in the heart during cardiac cycle ensure efficient pumping of the blood into the arteries. (3)

• M1: Pressure increases in the ventricles

• M2: Greater pressure in the ventricles than in {atria/ arteries}

• M3: Causing atrioventricular valves to close

• M4: Causing the semi lunar valves to open/ forcing blood into the arteries

Describe how the AV valves work during one cardiac cycle. (3)

• M1: the valves are open {when atria contract / atrial systole / when blood pressure greater in atria (than ventricles)}

• M2: The valves close {when ventricles contract / during ventricular systole/when pressure greater in ventricles (than atria)}

• M3: Valves prevent backflow of blood into the atria during ventricular systole

The structure of the pulmonary vein is different from the structure of the pulmonary artery.

Explain how this difference is related to the function of the pulmonary vein. (2)

• M1: {larger lumen/ less muscle in walls/ thinner walls}

• M2: {larger lumen as blood pressure lower/ less muscle because contraction not needed to push blood back to the heart}