Why man hot

All members of the animal Kingdom is divided into warm-blooded and cold-blooded. Body temperature the first, to which belong mammals and birds, is constant and does not depend on the environmental conditions. But man it can be cold and hot – why?

Instruction

1. Normal temperature on the body surface of a healthy adult is in the range of 36.4-36.9 degrees Celsius. Heat is formed throughout the body as a result of metabolism, mainly of the breakdown of carbohydrates and fats. Constancy of body temperature is ensured by the mechanisms of thermoregulation.
2. Regulation of the processes of heat generation and heat transfer by the Central nervous system. Centers of thermoregulation are located in the intermediate brain. Physiological adaptability to fluctuations in the external temperature can only occur to a certain stage – excessive overheating or overcooling can be life-threatening.
3. The body not only produces, but also gives off heat. The ratio of these processes may vary: the more heat is formed or comes from the environment, the more it should stand out, and Vice versa. For enhanced heat transfer skin capillaries dilate, starts sweating, and the evaporation of liquid from the surface cools the body.
4. Man getting hot under high ambient temperature, improper clothing, after consuming hot food and drinks. Intense heat generation occurs during active physical work and under stress, when such work, the "opinion" of the body, planned (preparation for fight or flight).
5. Excessive heat is dissipated not only through sweating but also by direct heat exchange with the environment, and radiation. Therefore, people who have this heat exchange prevents a thick layer of subcutaneous fat, sweat more in the heat and worse at taking it, but less freeze in the cold.
6. Body temperature may rise because of a fever, the body's response to any infectious or inflammatory process. The main role is played by pathogenic microorganisms and their toxins circulating in the blood. Enhanced metabolism at the elevated temperature contributes to an increase in the number of leukocytes and activation, thus, immunity therefore, this reaction can be called adaptive, although in some cases it exhausts the patient and leads him to death. When sudden nervous excitement, brain injuries or increased thyroid function possible neurogenic fever.