# A runner finishes a long-distance race on a hot day. Their body temperature rises above the normal level. Describe how the body uses a negative feedback system to restore normal body temperature.

> OCR GCSE Biology A: Gateway Science (J247) — B3.3 Maintaining internal environments · Describe · 4 marks

> During intense exercise in warm conditions, the body produces large amounts of heat, causing core body temperature to rise above its set point of approximately 37 °C.

## Mark scheme (4 marks)

1. The rise in body temperature is detected (by a receptor / the hypothalamus)
2. Effectors are activated to reduce body temperature (e.g. sweat glands produce sweat / vasodilation of blood vessels near the skin surface)
3. Heat is lost from the body so body temperature decreases / returns towards normal (37 °C)
4. This is a negative feedback system because the response reverses / opposes the original change (rise in temperature)

## Key terms

- [negative feedback system](https://www.gradenine.co.uk/glossary/negative-feedback-system)

## Related

- [Revision notes for OCR GCSE Biology A: Gateway Science (J247)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/a-runner-finishes-a-long-distance-race-c1439006) · Published by Druglandscape Ltd.