Thermoregulation (heat transfer) is a set of physiological processes in the organism of warm-blooded animals and humans, providing a constant body temperature at a certain level with very little hesitation.
The temperature of the internal environment of the body is maintained at a relatively constant level on the principle of self-regulation, according to which the deviation of temperature from level to ensure the normal functioning, is the stimulus that returns it to this level. A set of structures that self-regulation of the temperature of the body, is the so-called functional system of thermoregulation (P. K. Anokhin).
The constant temperature of the body is provided by two opposite processes - heat production and heat loss.
The heat production, i.e. heat generation in the organism depends on the intensity of metabolic processes, so it is often called chemical teploregulyation. The heat transfer surface of the body into the environment as a physical teploregulyation.
Heat the organism is carried out by (convection), radiation (radiation) and evaporation of sweat.
At high ambient temperatures, the heat loss by the Organism of warm-blooded animals whose skin is almost devoid of sweat glands (e.g. dogs), additionally through evaporation of sweat, and also due to evaporation from the surface of the respiratory tract. Finally, some of the heat out from the body with urine and faeces.
If the processes of heat production prevail over the processes of heat transfer, there comes the overheating of the body (see). If, on the contrary, the processes of heat transfer prevail over the processes of heat production, comes cooling (see).
In thermoregulation participate both humoral and neural mechanisms.
Temperature fluctuations of ambient air act on special receptor education that is sensitive to temperature change (thermoreceptors). There are heat and cold receptors. The excitement of thermoreceptors arrives at a special conduction paths in the brain and causes changes in the activity of thermoregulation center located in the hypothalamus. Excitation of various departments of the centre leads to the change of the processes of heat production and heat loss. When you turn off the center of thermoregulation special chemicals, the body loses the ability to maintain constant temperature. This feature in recent years use in the clinic for artificial cooling of the organism during a difficult surgical operations on heart.