A student states: 'The heart is just a simple pump that pushes blood around the body in one direction.' Evaluate this statement, referring to the structure and function of the heart.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
The human heart beats approximately 70 times per minute at rest, pumping blood through two separate circulation loops.
Model answer (5 marks)
The heart is a pump, but it is not a single‑loop pump.
1. It is a double pump – two sides (right and left) work simultaneously.
2. The right side receives deoxygenated blood, pumps it through the pulmonary circulation to the lungs.
3. The left side receives oxygenated blood from the lungs and pumps it through the systemic circulation to the rest of the body.
4. Four valves (tricuspid, pulmonary, mitral, aortic) ensure unidirectional flow and prevent back‑flow.
5. Therefore the statement is overly simplistic; the heart’s structure and dual circulation make it far more complex than a single‑direction pump.
1. It is a double pump – two sides (right and left) work simultaneously.
2. The right side receives deoxygenated blood, pumps it through the pulmonary circulation to the lungs.
3. The left side receives oxygenated blood from the lungs and pumps it through the systemic circulation to the rest of the body.
4. Four valves (tricuspid, pulmonary, mitral, aortic) ensure unidirectional flow and prevent back‑flow.
5. Therefore the statement is overly simplistic; the heart’s structure and dual circulation make it far more complex than a single‑direction pump.
Examiner tips
- Mention the double‑pump nature and the two circulations; include the valves; explain why the statement is incomplete.
- Use the exact terms ‘pulmonary’ and ‘systemic’ circulation and the valve names to gain full marks.
Common mistakes
- Saying the heart only has one side or one circulation; forgetting the valves; using vague terms like ‘blood flows in one direction’ without naming the valves or the two circuits.
Mark scheme (5 marks)
- The student is correct that the heart acts as a pump / the heart pumps blood around the body
- The heart is a double pump / has two sides (left and right) that pump blood separately / simultaneously
- The right side pumps deoxygenated blood to the lungs (pulmonary circulation) and the left side pumps oxygenated blood to the rest of the body (systemic circulation)
- Valves (e.g. atrioventricular / semilunar valves) ensure blood flows in one direction only / prevent backflow of blood
- The statement is therefore too simple / incomplete because the heart is a double pump with two circuits / it is more complex than described
Related
- All Pearson Edexcel A-Level Biology A (9BI0) revision notes →
- How to answer a "Evaluate" question →
- Decode the mark scheme abbreviations →
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