the way constant conditions are maintained in the body in spite of the changes in surroundings. (Skin is responsible for this)
What does sweat do?
takes latent heat of evaporation from the body (and so cools it) as it changes from liquid to vapour.
What does vasodilation means?
Widening of blood vessels (capillaries dilate) so more heat is lost by radiation. (Happens when very hot)
What does vasoconstriction mean?
Narrowing of blood vessels ( capillaries constrict) so less heat is lost (Happens when very cold)
What does fats do?
insulates and protects heat loss also a respiratory substrate so it is a heat source
What does hair do?
insulates but less important to humans than other mammals
What does shivering do?
muscle action generates heat do to increased respiration
Mechanism of Homeostasis
Normal State-> change environment->corrective mechanism working in opposite direction to change (negative feed back) {THIS CYCLE USUALLY MAINTAINS STEADY STATE}-> Normal State
2. Mechanism of Homeostasis
Normal State-> change in the environment-> corrective mechanism(break down)-> further change( in same direction as original change)(positive feedback)-> new equilibrium or death
