2.77b Thermoregulation

Homeostasis - maintenance of a constant internal environment

Receptor   ->   Co-ordinator    ->    Effector
(e.g brain)                      (37/38 degrees)                       (skin)

     ^
stimuli
(Temp of body, blood)

When to hot:

The blood vessel within the skin dilate/widen so more blood flows to the surface, increasing the exchange of heat to the outside of the body by; sweat, radiation, flat hairs.

Cools to blood and returns to body temp to its optimum temp. 

When too cold:

Skin reacts with shivering and raised hairs 

This forces the blood to travel deep within the tissues and reduces the heat exchange with the external environment