B7- controlling body temp
- Created by: superlouasaur
- Created on: 27-04-15 16:56
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- Controlling body temperature
- Body temperature must be kept constant
- The body has to balance the amount of heat energy gained (e.g. through respiration) and lost to keep the core body temp constant
- Temperature receptors in the skin detect the external temperature, and receptors in the hypothalamus (a part of the brain) detect the temperature of the blood
- The nervous system helps to control body temperature, using the following negative feedback mechanism
- The body has some nifty tricks for altering its temperature
- Too hot
- Vasodilation- blood vessels close to the skin's surface get bigger in diameter
- This means that more blood gets to the surface of the skin.
- The warm blood then loses more of its heat to the surroundings.
- Sweating- when the water in the sweat evaporates heat is used, which cools the body.
- Vasodilation- blood vessels close to the skin's surface get bigger in diameter
- Too cold
- Vasoconstriction- blood vessels close to the skin's surface get smaller in diameter
- This means that less blood gets to the surface of the skin, which stops the blood losing as much heat to the srroundings
- You shiver- your muscles contract rapidly. This increases the rate of respiration and warms the tissue surrounding the muscles
- Vasoconstriction- blood vessels close to the skin's surface get smaller in diameter
- Too hot
- Body temperature must be kept constant
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