Question

Explain the terms vasodilation and vasoconstriction. How do these processes contribute to the temperature regulation of the body?

Answer 1

When the body temperature is too high hypothalamus sends signals to the capillaries that supply blood to the skin to dilate (vasodilation). This leads to more blood flow to the capillaries and hence heat is lost. Similarly, when the body temperature is too low the hypothalamus sends signals to the capillaries to contract (vasoconstriction), reducing blood flow and hence heat loss is reduced.