Explain the main thermoregulatory processes in humans.

Thermoregulation involves both trying to increase and decrease our body temperature in order to maintain a temperature of 37 degrees celsius. Four main processes exist- convection, conduction, radiation and evaporation. Convection occurs when a liquid or gas moves past the body, resulting in the transfer of heat. Conduction occurs when two objects come in direct contact with each other. Heat transfers from areas of high temperature to areas of low temperature . Radiation is the most important process in humans. When body temperature rises, a response known as vasodilatation occurs. This is the widening of blood vessels near the surface of the skin, allowing more warm blood to flow through them. This results in increased heat loss from the blood via radiation. Alternatively if body temperature drops, vasoconstriction occurs. This is where blood vessels narrow, resulting in less warm blood flowing through the vessels and therefore less loss of heat via radiation. Finally evaporation occurs after the process of perspiration (sweating). Perspiration is controlled by the sympathetic nervous system and results in sweat on the surface of the skin which can then evaporate, producing a cooling effect.