Coronary Heart Disease

Question 1

Explain why a blood clot in a coronary artery is likely to result in a heart attack.

Answer 1

Region is deprived of blood and therefore oxygen; So cannot respire aerobically so Muscle cannot contract OR.. So must respire anaerobically So lactate is formed; (Both) leading to the tissue of the heart dying

Question 2

Explain how:

• Plasma cholesterol
• High blood pressure
• Smoking

can increase risk of heart disease

Answer 2

Plasma cholesterol:
More laid down in lining of arteries;
Walls of arteries damaged / weaken;
Arteries are narrowed;
Aneurysm forms;
Clot forms;

High blood pressure:
Increases rate at which cholesterol is laid down;
Higher fibrinogen levels;
Clots form (once only);

Smoking:
Increases blood pressure:
Muscle in artery becomes thicker / lumen narrower; (max 2)

Question 3

Describe and explain how atheroma can lead to myocardial infarction.

Answer 3

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