Question

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

Answer 1

• Vasodilation - It is the dilation of blood vessels that leads to an increase in the blood supply.
• Vasoconstriction - It is the narrowing of the blood vessels causing reduction in the blood supply to the skin.

Vasodilation and vasoconstriction helps in regulating body temperature by following ways:

In cold weather

• The blood vessels are narrowed at lower temperatures that lead to reduced blood supply to the skin (vasoconstriction).
• Loss of heat is less by conduction, radiation, convection, vaporization as reduced blood supply lowers the secretion of sweat by sweat glands.

In hot weather

• Blood supply to the skin is increased at higher temperatures by dilation of blood vessels in the skin (Vasodilation).
• Loss of heat is high by conduction, convection and radiation and vaporization as more sweat is produced because of rich blood supply to the skin.