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LearnYBI11WBI11 · Unit 1: Molecules, Diet, Transport and HealthMolecules, transport and healthCardiovascular disease and risk
Molecules, transport and health · Subtopic 4 of 4

Cardiovascular Disease and Risk

Atherosclerosis: damage to the artery endothelium (e.g. high blood pressure, smoking) triggers an inflammatory response; white cells and LDL cholesterol build up as an atheroma (plaque), which hardens and narrows the artery. Plaques can rupture, triggering blood clotting: platelets release thromboplastin → prothrombin → thrombin (needs Ca²⁺, vitamin K) → fibrinogen → fibrin mesh traps cells → thrombus. A clot in a coronary artery causes a heart attack (myocardial infarction); in the brain, a stroke. Risk factors: genes, age, male sex, high blood pressure, smoking, high LDL, obesity, inactivity, high salt. Measures: BMI = mass (kg) ÷ height² (m²), waist-to-hip ratio, energy budget. Treatments: antihypertensives (lower pressure), statins (lower LDL), anticoagulants and platelet inhibitors (reduce clotting; risk of bleeding).

Edexcel YBI11 WBI11≈ 45 minRevision 1 · updated 2026-11-02
Section 1 of 14

Learning objectives

  • Describe atherosclerosis and blood clotting.
  • Explain risk factors.
  • Calculate BMI and interpret risk data.
  • Evaluate treatments.
Pause and think

Why are arteries, not veins, damaged by atherosclerosis?

Section 2 of 14

Core idea

Start hereThe silent build-up

Atherosclerosis can develop for decades without symptoms, until a clot blocks a coronary artery.

The big idea

Damage to artery linings leads to plaques; a ruptured plaque triggers clotting that can block blood flow to the heart or brain.

From damage to heart attack

Atherosclerosis and thrombosis.

Worked exampleBMI

80 kg, 1.80 m.

Goal
BMI.
Strategy
mass ÷ height².
  1. 1.802=3.241.80^2=3.24
    Square height.
  2. 803.24=24.7\frac{80}{3.24}=24.7
    Divide.
Answer24.7 kg m⁻².
✓ CheckWithin healthy range ✓.

Summary

  • Atheroma and thrombosis.
  • Risk factors.
  • Treatments and risks.
Key words
Atheroma
Fatty plaque in an artery wall.
Thrombosis
Formation of a blood clot inside a vessel.
HistoryFramingham Heart Study. Since 1948 the town of Framingham, Massachusetts, has been studied for heart disease; it identified smoking, cholesterol and high blood pressure as risk factors.
Fun factAspirin and clotting. Low-dose aspirin reduces platelet stickiness, which is why some heart patients take it daily.
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