February 19, 2012

2.88 Temperature regulation

2.88 describe the role of the skin in temperature regulation, with reference to sweating, vasoconstriction and vasodilation

Stimulus: Temperature of internal body temperature (blood temp)
Receptor: Hypothalamus (as blood flows through this part of the brain)
Coordinator: Hypothalamus (the part of the brain associated with thermoregulation)
Effector: Skin

Cooling down

  • Sweat glands produce sweat which evaporates from the body creating a cooling effect.
  • Vasodilation - Blood flows to the surface of the skin through dilated vessels so that heat can potentially radiate off of the body.
  • Furthermore the radiating heat from the blood increases the evaporation of sweat, this is known as latent heat of evaporation.
Heating up

  • Vasoconstriction - Capillaries near the surface of the skin narrow to keep heat inside of the body
  • Shivering – a reflex to increase body temperature, muscles groups near vital organs shake in an attempt to create warmth.
  • Hair erection – hair stands up to trap a layer of air close to the skin. (air is a poor conductor of heat)

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