Thermoregulation - Blood Vessels
Biology: Cambridge International GCSE Supplement, topic 14.4.10
Thermoregulation - Blood Vessels
Arterioles supplying the capillary networks of the skin have layers of smooth muscle tissue in their walls. They respond differently when we are too hot or too cold.
Too hot
- If we are too hot, then the muscular walls relax.
- This is called vasodilation.
- This allows more blood to enter and flow through capillaries close to the skin surface. The excess heat energy is transferred to the surroundings.
Too cold
- If we are too cold, then the muscular walls contract.
- This is called vasoconstriction.
- This reduces the blood flow to the skin surface and heat energy is kept inside the body.
Test yourself on Thermoregulation - Blood Vessels
Which of the following are true of vasodilation?