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Transport in Animals: Question 2

Syllabus 9.2

Structured Core 9 marks

A workplace wellness programme offers free heart check-ups to employees aged over 40. During each check-up, a nurse takes several measurements of heart activity and asks each employee about their diet, exercise habits, smoking history and family medical history, before giving health advice.

(a) State two ways, other than measuring blood pressure, in which the activity of a person's heart can be monitored. [2]

(b) Describe coronary heart disease in terms of what happens to the coronary arteries. [2]

(c) State three risk factors, other than age and sex, that increase a person's chance of developing coronary heart disease. [3]

(d) Discuss how (i) a change in diet and (ii) an increase in exercise could each reduce an employee's risk of developing coronary heart disease. [2]

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Worked solution

Part (a): Monitoring heart activity

Aside from blood pressure, a person’s heart activity can be monitored by recording an electrocardiogram (ECG), which shows the electrical activity that triggers each heartbeat, by measuring the pulse rate, or by listening to the sounds made as the heart valves close, for example with a stethoscope. Any two of these are creditable.

Part (b): Coronary heart disease

The heart muscle needs its own supply of oxygenated blood, which it receives through the coronary arteries. In coronary heart disease, these coronary arteries become narrowed or blocked, often by a build-up of fatty deposits on their inner walls. This reduces the flow of oxygen and glucose reaching the heart muscle, which can damage the muscle or cause a heart attack.

Part (c): Risk factors

Besides age and sex, several other factors increase the risk of coronary heart disease. Any three of the following are creditable: a diet high in fat and/or salt, a lack of exercise, stress, smoking, and a genetic predisposition (a family history of heart disease).

Part (d): Reducing the risk through diet and exercise

(i) Diet: A diet lower in fat and salt means less fatty material is available to build up inside the walls of the coronary arteries. This reduces the chance that an artery becomes narrowed or completely blocked.

(ii) Exercise: Regular exercise strengthens the heart muscle, making it pump more efficiently, and helps to control body mass and blood pressure. Lower blood pressure and body mass both reduce the strain on the coronary arteries and the likelihood of fatty deposits building up.

Final answers

  • (a) Any two of: ECG, pulse rate, listening to valve sounds.
  • (b) Coronary arteries supplying the heart muscle become narrowed/blocked (e.g. by fatty deposit), reducing oxygen/glucose supply to heart muscle.
  • (c) Any three of: diet high in fat/salt, lack of exercise, stress, smoking, genetic predisposition.
  • (d) (i) Better diet reduces fatty deposit build-up in coronary arteries. (ii) More exercise strengthens the heart and controls body mass/blood pressure, lowering risk.