Explain how the body responds when core body temperature rises above the normal level.

Edexcel GCSE Biology (1BI0) — 7.2 Homeostasis · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

The normal core body temperature in humans is approximately 37 °C. During vigorous exercise, core body temperature can increase significantly above this level.

Model answer (4 marks)

Receptors in the hypothalamus (or skin) detect the rise in core body temperature
Sweat glands produce more sweat / sweating increases
Water in sweat evaporates from the skin surface, transferring heat energy away from the body
Vasodilation of blood vessels near the skin surface increases heat loss / returns temperature to normal (negative feedback)

Examiner tips

  • Use the word ‘detect’ for receptors, ‘produce’ for sweat glands, ‘evaporates’ for heat transfer, and ‘vasodilation’ for blood vessels
  • Show the sequence of events as a clear chain of cause and effect
  • Include the term ‘negative feedback’ to link the response to homeostasis

Common mistakes

  • Mixing up ‘conduction’ with ‘evaporation’ for heat loss
  • Omitting the role of the hypothalamic receptors
  • Failing to mention negative feedback or vasodilation

Mark scheme (4 marks)

  1. Receptors in the hypothalamus (or skin) detect the rise in core body temperature
  2. Sweat glands produce more sweat / sweating increases
  3. Water in sweat evaporates from the skin surface, transferring heat energy away from the body
  4. Vasodilation of blood vessels near the skin surface increases heat loss / returns temperature to normal (negative feedback)

Related

More Homeostasis questions

▶ Try answering this question with AI marking (free) →