A patient visits their doctor and is told they have high blood cholesterol levels and high blood pressure. The doctor explains that both of these are risk factors for cardiovascular disease. Explain how having high blood cholesterol levels and high blood pressure can lead to a heart attack.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Cardiovascular disease is one of the leading causes of death in the UK. Lifestyle choices and certain medical conditions can increase a person's risk of developing the disease.
Model answer (5 marks)
1. High blood cholesterol causes fatty deposits (atheroma) to build up in artery walls.
2. These deposits narrow the arteries (atherosclerosis), reducing blood flow.
3. High blood pressure damages the artery walls, favouring further fatty‑deposit formation.
4. A clot can form on a fatty deposit, producing thrombosis that blocks a coronary artery.
5. The blockage stops oxygenated blood to the heart muscle, causing myocardial necrosis – a heart attack.
2. These deposits narrow the arteries (atherosclerosis), reducing blood flow.
3. High blood pressure damages the artery walls, favouring further fatty‑deposit formation.
4. A clot can form on a fatty deposit, producing thrombosis that blocks a coronary artery.
5. The blockage stops oxygenated blood to the heart muscle, causing myocardial necrosis – a heart attack.
Examiner tips
- Use the exact terms: atheroma, atherosclerosis, thrombosis, myocardial necrosis. Show the causal chain from risk factor to heart attack. Keep each point short and focused on one mark point.
Common mistakes
- Mixing up atherosclerosis with hypertension. Using vague phrases like "bad cholesterol" instead of specifying high LDL. Failing to mention the clot (thrombosis) as the immediate cause of the heart attack.
Mark scheme (5 marks)
- High blood cholesterol leads to the build-up of fatty deposits (atheroma) inside the walls of arteries
- This causes the arteries to narrow (atherosclerosis), restricting blood flow
- High blood pressure causes damage to the artery walls, making the build-up of fatty deposits more likely
- A blood clot (thrombosis) can form at the site of a fatty deposit, which may block the coronary artery
- This prevents oxygenated blood reaching the heart muscle, causing the heart muscle to die (heart attack)
Key terms in this question
Related
- All Edexcel A-Level Biology A: Salters-Nuffield (9BN0) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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