A rescue worker completes a step test while carrying equipment. The worker's pulse and stroke volume are measured at rest and during the test.
cardiac output=stroke volume×heart rate \text{cardiac output} = \text{stroke volume} \times \text{heart rate} cardiac output=stroke volume×heart rate| condition | pulse beats counted in 30 s | stroke volume in cm3 beat−1\mathrm{cm^3\,beat^{-1}}cm3beat−1 |
|---|---|---|
| at rest | 34 | 75 |
| during the step test | 78 | 105 |
Calculate the increase in cardiac output from rest to during the step test.
Give your answer in dm3 min−1\mathrm{dm^3\,min^{-1}}dm3min−1.
Explain how the increase in cardiac output helps the worker's muscles to continue contracting during the step test.
67 exam-style questions on Edexcel GCSE Biology 8.2 Blood and circulation, covering 8.2.1 Structure and function of the blood, 8.2.2 Structure of blood vessels, 8.2.3 Structure of the heart and circulatory system, and 8.2.4 Cardiac output. Each one has a worked solution and a mark scheme showing where the marks go.