2.89 Describe the role of the skin in temperature regulation, with reference to sweating, vasoconstriction and vasodilation

Stimulus: body temperature
Receptor: hypothalamus (brain)
Effector: skin
Response: warming up / cooling down

It's important to keep our body temperature constant because most of our enzymes work best at about 37ºC. Keeping internal conditions within acceptable limits is known as homeostasis.

Too cold

• Shivering: generates heat in the muscles + from increased respiration
• Hairs stand on end: traps an insulating layer on the surface of your skin
• Vasoconstriction: capillaries near the surface of the skin narrow so they carry less blood and more heat is kept in
• Reduced sweating: because sweat cools you down and you don't want that!

Too hot

• Vasodilatation: capillaries widened and pushed towards the surface of the skin by this so more heat is lost through radiation and conduction
• Sweating: produced by sweat glands in your skin and it is heated by the body. When it evaporates, it takes the heat with it.
• Hairs lie flat: less air is trapped