Controlling Body Temperature

• Body temperature is monitored and controlled by the thermoregulatory centre in the brain
• The thermoregulatory centre contains receptors sensitive to the temperature of the blood
• The skin contains temperature receptors and sends nervous impulses to the thermoregulatory centre
• When the body temperature is too high

  • Sweat is produced from the sweat glands and evaporates, transferring energy to the environment
  • Blood vessels close to the surface dilate to transfer energy from the skin to the environment ( vasodilation )
• When the body temperature is too low

  • Pili erectile muscles contract to make hairs stand up and trap an insulating layer of air
  • Blood vessels close to the surface of the skin constrict to close off blood supply ( vasoconstriction )
  • Muscles contract and shiver to respire which releases some energy to the body