Thermoregulation - Blood Vessels
Biology: Edexcel IGCSE, topic 3.5.16
Thermoregulation - Blood Vessels
Blood vessels deep in 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?