# A patient is admitted to hospital with a dangerously high core body temperature of 41 °C following prolonged exercise in hot conditions. Explain how negative feedback mechanisms would act to return the patient's core body temperature to the normal set point of 37 °C.

> OCR A-Level Biology A (H420) — 5.1 Communication and homeostasis · Explain · 4 marks

> The hypothalamus acts as the thermoregulatory centre in humans, continuously monitoring blood temperature and coordinating responses through both nervous and hormonal pathways. Peripheral thermoreceptors in the skin also send afferent impulses to the hypothalamus.

## Mark scheme (4 marks)

1. The hypothalamus detects that blood temperature is above the set point / above 37 °C
2. Effectors are activated to promote heat loss — sweat glands increase sweat production and/or vasodilation of skin arterioles occurs
3. The corrective responses reduce core body temperature back towards the set point of 37 °C
4. Negative feedback is completed — once temperature returns to the set point, the hypothalamus no longer stimulates the effectors, so the corrective response is switched off

## Key terms

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

## Related

- [Revision notes for OCR A-Level Biology A (H420)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-patient-is-admitted-to-hospital-48ece399) · Published by Druglandscape Ltd.