Explain how the build-up of fatty deposits in a coronary artery can lead to a heart attack.

Pearson Edexcel A-Level Biology A (9BI0) — 1.1 Cardiovascular disease and risk · Explain · 5 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Cardiovascular disease is the leading cause of death in the United Kingdom. Atherosclerosis, the narrowing of arteries due to the build-up of fatty deposits called plaques, is a key underlying cause.

Model answer (5 marks)

Fatty deposits (plaques) accumulate in the coronary artery wall, narrowing the lumen.
Reduced blood flow through the artery limits oxygen and glucose delivery to the myocardium.
A plaque rupture can trigger a thrombus that may occlude the artery completely.
The resulting ischaemia means heart muscle cells cannot perform aerobic respiration and produce ATP.
Cell death (necrosis) of the myocardium then manifests as a heart attack.

Examiner tips

Use the exact sequence: plaque → lumen narrowing → reduced flow → clot → ischaemia → cell death
Show cause–effect links, not just list items
Mention the role of oxygen/glucose deprivation
Keep answer concise, 5 points

Common mistakes

Confusing atherosclerosis with hypertension
Failing to mention thrombus formation
Using vague terms like "heart damage" instead of cell death

Mark scheme (5 marks)

Fatty deposits (plaques/atheroma) build up in the wall of the coronary artery, causing the lumen to narrow
Reduced blood flow (through the coronary artery) to the heart muscle
A blood clot (thrombus) can form at the site of the plaque, which may block the artery completely
Less oxygen (and glucose) is delivered to the heart muscle cells
Heart muscle cells cannot respire / produce enough energy, causing them to die, resulting in a heart attack

Key terms in this question

coronary artery · heart attack