Temperature Control

Our body temperature must be controlled within a very narrow range so that our body can function properly. A constant core temperature of around 37ºC needs to be maintained. The thermoregulatory centre of the brain triggers changes in effectors, such as sweat glands and muscles, in order to constantly balance our temperature gains and temperature losses.

Temperature receptors in the skin detect changes in external temperature. Sensory and relay neurons transmit this information as impulses to the thermoregulatory centre of the brain - area of brain responsible for monitoring and controlling temperature.

When the body is too cold: 

• The blood cells supplying the skin capillaries constrict (get narrow) causing less blood to flow nearer to the surface of the skin, causing the skin to become pale and reduce heat loss 
• The body shivers- Twitching of the muscles generates heat as their contraction causes the muscles to respire making energy which warms the body

When the body gets too hot:

• The blood vessels supplying the skin capillaries dilate causing more blood to flow nearer the surface of the skin, the skin to become red in appearance, and an increase in heat loss.

• The body sweats - which increases heat loss due to the large amount of heat energy required to evaporate the water.