2.88 describe the role of the skin in temperature regulation, with reference to sweating, vasoconstriction and vasodilation
To maintain even temperature in the body, the skin goes through changes. Temperature control is a good example of negative feedback. In a negative feedback system, any change will make the system respond in a way that minimises the change.
When it is too cold
- Vasoconstriction: blood capillaries in the skin become narrower so they carry less blood close to the surface. Heat is kept inside the body.
- Sweating is reduced
- Hair erection: muscles make the hairs stand up to trap a layer of air as insulation
- Shivering: the muscle action of shivering releases extra heat from the increased respiration.
- A layer of fat under the skin acts as insulation.
When it is too hot
- Vasodilation: blood capillaries in the skin widen so they carry more blood close to the surface. Heat is transferred from the blood to the skin by conduction, then to the environment by radiation.
- Sweating takes place because heat gets evaporated.
- Hairs lay flat so less air is trapped.
- No shivering.
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