9.2

Heart

Cambridge IGCSE Biology (0610)  · Unit 9: Transport in animals  · 12 flashcards

Heart is topic 9.2 in the Cambridge IGCSE Biology (0610) syllabus , positioned in Unit 9 — Transport in animals , alongside Circulatory systems, Blood vessels and Blood.  In one line: Coronary heart disease involves the blockage of coronary arteries, often due to a build-up of fatty deposits. A major risk factor is a diet high in saturated fat, which contributes to plaque formation in the arteries.

This topic is examined in Paper 1 (multiple-choice) and Papers 3/4 (theory), plus Paper 5 or Paper 6 (practical / alternative to practical). Past papers from 2022 to 2025 record 3 explicit questions on this topic — though the concept underpins many adjacent topics, so it is tested far more often than that figure suggests.

The deck below contains 12 flashcards — 1 definition, 6 key concepts, 1 process card, 2 application cards and 2 identification cards — covering the precise wording mark schemes reward.  Use the definition card to lock down command-word answers (define, state), then move on to the concept and application cards to handle explain, describe and compare questions.

Key definition

Describe coronary heart disease and one possible risk factor

Coronary heart disease involves the blockage of coronary arteries, often due to a build-up of fatty deposits. A major risk factor is a diet high in saturated fat, which contributes to plaque formation in the arteries.

What the Cambridge 0610 syllabus says

Official 2026-2028 spec

These are the exact learning objectives Cambridge sets for this topic. Match the command word (Describe, Explain, State, etc.) in your answer to score full marks.

  1. Identify Identify in diagrams and images the structures of the mammalian heart, limited to: muscular wall, septum, left and right ventricles, left and right atria, one-way valves and coronary arteries
  2. State State that blood is pumped away from the heart in arteries and returns to the heart in veins
  3. State State that the activity of the heart may be monitored by: ECG, pulse rate and listening to sounds of valves closing
  4. Investigate Investigate and describe the effect of physical activity on the heart rate
  5. Describe Describe coronary heart disease in terms of the blockage of coronary arteries and state the possible risk factors including: diet, lack of exercise, stress, smoking, genetic predisposition, age and sex
  6. Discuss Discuss the roles of diet and exercise in reducing the risk of coronary heart disease
  7. Identify Identify in diagrams and images the atrioventricular and semilunar valves in the mammalian heart Supplement
  8. Explain Explain the relative thickness of: (a) the muscle walls of the left and right ventricles (b) the muscle walls of the atria compared to those of the ventricles Supplement
  9. Explain Explain the importance of the septum in separating oxygenated and deoxygenated blood Supplement
  10. Describe Describe the functioning of the heart in terms of the contraction of muscles of the atria and ventricles and the action of the valves Supplement
  11. Explain Explain the effect of physical activity on the heart rate Supplement
Key Concept Flip

Name the four chambers of the mammalian heart.

Answer Flip

The four chambers are the left atrium, right atrium, left ventricle, and right ventricle. The atria receive blood, while the ventricles pump blood out of the heart to other parts of the body such as the lungs.

Key Concept Flip

What is the role of the coronary arteries?

Answer Flip

Coronary arteries supply the heart muscle itself with oxygenated blood. Blockage of these arteries can lead to coronary heart disease.

Example: a blockage can cause angina or a heart attack.
Key Concept Flip

Describe how the activity of the heart can be monitored.

Answer Flip

Heart activity can be monitored by using an electrocardiogram (ECG) to measure electrical activity, checking pulse rate to measure heart beats per minute, and listening for the sounds of valves closing with a stethoscope.

Key Concept Flip

How does physical activity affect heart rate?

Answer Flip

Physical activity increases heart rate. This is because muscles need more oxygen and glucose, so the heart pumps more blood to deliver these substances more quickly, ensuring cells like those in the quadriceps get enough nutrients.

Definition Flip

Describe coronary heart disease and one possible risk factor.

Answer Flip

Coronary heart disease involves the blockage of coronary arteries, often due to a build-up of fatty deposits. A major risk factor is a diet high in saturated fat, which contributes to plaque formation in the arteries.

Key Concept Flip

What are the roles of diet and exercise in reducing the risk of coronary heart disease?

Answer Flip

A balanced diet, low in saturated fats and cholesterol, helps prevent plaque build-up in arteries. Regular exercise strengthens the heart muscle, improves blood flow, and helps maintain a healthy weight, reducing strain on the heart.

Key Concept Flip

Distinguish between atrioventricular and semilunar valves.

Answer Flip

Atrioventricular valves (tricuspid and mitral) are located between the atria and ventricles, preventing backflow into the atria when ventricles contract. Semilunar valves (pulmonary and aortic) are located at the exit of the ventricles, preventing backflow into the ventricles when they relax.

Key Concept Flip

Explain why the left ventricle wall is thicker than the right ventricle wall.

Answer Flip

The left ventricle pumps blood to the entire body, requiring more force to overcome the higher resistance in the systemic circulation. The right ventricle only pumps blood to the lungs, a shorter distance with lower resistance. Therefore the left ventricle has a thicker and stronger muscle.

Key Concept Flip

Why are the walls of the atria thinner than the walls of the ventricles?

Answer Flip

The atria only need to pump blood a short distance into the ventricles. Ventricles need to pump blood further, either to the lungs (right ventricle) or the whole body (left ventricle), which requires stronger contractions and thus thicker walls.

Key Concept Flip

What is the function of the septum in the heart?

Answer Flip

The septum is a muscular wall that separates the left and right sides of the heart. This separation prevents the mixing of oxygenated and deoxygenated blood, ensuring that oxygen-rich blood is delivered efficiently to the body.

Key Concept Flip

Describe the functioning of the heart in terms of atrial and ventricular contraction.

Answer Flip

First, the atria contract, pushing blood into the ventricles. Then, the ventricles contract, pumping blood out to the lungs (right ventricle) and the rest of the body (left ventricle). Valves ensure blood flows in one direction, preventing backflow.

Key Concept Flip

Explain the effect of physical activity on the heart rate using biological principles.

Answer Flip

During physical activity, the body needs more oxygen and glucose for respiration in muscle cells. Chemoreceptors detect changes in blood pH, signaling the brain to increase heart rate. This delivers more oxygenated blood to active muscles like the biceps, supporting increased energy production.

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9.1 Circulatory systems 9.3 Blood vessels

Key Questions: Heart

Describe coronary heart disease and one possible risk factor.

Coronary heart disease involves the blockage of coronary arteries, often due to a build-up of fatty deposits. A major risk factor is a diet high in saturated fat, which contributes to plaque formation in the arteries.

Tips to avoid common mistakes in Heart

More topics in Unit 9 — Transport in animals

Heart sits alongside these Biology decks in the same syllabus unit. Each uses the same spaced-repetition system, so progress in one informs the next.

Cambridge syllabus keywords to use in your answers

These are the official Cambridge 0610 terms tagged to this section. Mark schemes credit responses that use the exact term — weave them into your answers verbatim rather than paraphrasing.

heart atrium ventricle valve septum aorta vena cava pulmonary artery pulmonary vein cardiac muscle heart rate pulse coronary artery pacemaker

Key terms covered in this Heart deck

Every term below is defined in the flashcards above. Use the list as a quick recall test before your exam — if you can't define one of these in your own words, flip back to that card.

Describe coronary heart disease and one possible risk factor

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How to study this Heart deck

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