This higher tier covers Higher Thermoregulation in More Detail within Temperature Regulation for GCSE Biology. Topic 5: Temperature Regulation It is section 10 of 13 in this topic. This section is most useful once the core foundation idea is secure, because it adds the detail that pushes answers higher.
Higher Thermoregulation in More Detail
At higher tier, you may be asked to explain the precise mechanism of vasodilation and vasoconstriction in terms of the blood vessels involved:
- The skin contains capillary networks beneath the surface. Blood flow to these capillaries is controlled by arterioles (small arteries) that have muscular walls.
- During vasodilation: arteriole muscles relax → lumen widens → more blood enters capillaries near skin surface → more heat lost
- During vasoconstriction: arteriole muscles contract → lumen narrows → less blood reaches surface capillaries → less heat lost
- In some descriptions, blood may be diverted through deeper vessels (shunt vessels) away from the surface during cold conditions, further reducing heat loss.
You may also be asked to explain why the hypothalamus is both a receptor AND a coordination centre: thermoreceptors within the hypothalamus itself detect changes in blood temperature (as blood flows through the hypothalamus), meaning it senses the change and coordinates the response simultaneously.
Practice questions for Temperature Regulation
What is the normal core body temperature in humans?
Explain how sweating helps to reduce body temperature.