Learn how negative feedback keeps core temperature near 37 °C: thermoreceptors signal the hypothalamus, which coordinates responses such as sweating, skin blood-flow changes and shivering.
Explain the control of body temperature in humans.
normal body core temperature constant/ 36.5 to 37.5∘C;
(accept single values within this range);
regulated by negative feedback/homeostatic mechanisms;
hypothalamus is the centre of thermoregulation;
hypothalamus sends impulses to the body to increase/decrease temperatures;
release of sweat (by sweat glands in the skin) if skin temperature rises;
evaporation of water cools the body;
(concept of evaporation must be mentioned)
heat is transferred by blood;
transfer of heat from body core in blood to surface;
if temperature rises, increased flow of blood/heat to the skin/vasodilation of skin blood vessels/arterioles;
(do not accept veins, arteries or capillaries)
if temperature drops, decreased flow of blood/heat to the skin/vasoconstriction of skin blood vessels/arterioles;
(eg reducing activity (to lower body temperature) / reducing exposed surfaces (to reduce heat loss)