A researcher measures the blood flow through the coronary arteries of a healthy adult at rest and during cycling. Every 100 cm3 of blood carries 20 cm3 of oxygen.
| Activity | Blood flow through the coronary arteries in cm3 per minute |
|---|---|
| Rest | 250 |
| Cycling | 750 |
Calculate the volume of oxygen delivered to the cardiac muscle each minute during cycling.
A second adult has coronary heart disease. Fatty material in their coronary arteries means that the blood flow through them cannot rise above 400 cm3 per minute. Assume their cardiac muscle needs the same blood flow as the healthy adult's.
Use the data to explain why this person gets chest pain when cycling but not at rest.
304 exam-style questions on AQA GCSE Biology 2.2 Animal tissues, organs and organ systems, covering 2.2.1 The human digestive system, 2.2.2 The heart and blood vessels, 2.2.3 Blood, 2.2.4 Coronary heart disease: a non-communicable disease, 2.2.5 Health issues, 2.2.6 The effect of lifestyle on some non-communicable diseases, and 2.2.7 Cancer. Each one has a worked solution and a mark scheme showing where the marks go.