Khankeldiev Sh. Kh. Regional features of the physical status of youth students fergana 2022 Reviewer

1.5.2. SWEAT SYSTEM
The main signal for the start of sweating is a change in the temperature of the skin and internal body temperature. These reactions are under normal physiological conditions under the control of the hypothalamus, although in some conditions, both sweating and vasodilation can be regulated already at the spinal level.
The boundary values ​​of body temperature, at which the sweat glands begin to become active, do not remain constant. The mechanisms that determine this boundary value (the so-called "setting point") have recently been the subject of lively research. We will not go into this issue in detail here, we will only note that all modern concepts of thermoregulation are largely based on the ideas of automatic control of systems with feedback. It is assumed that after the "setting point" is somehow determined, further temperature regulation occurs according to the well-known feedback mechanism. If the body temperature rises more than the "set point", the mechanisms of heat transfer, in particular, sweating, increase. As for the level control system of the "setting point" itself, as far as one can judge from the review mentioned above, this is still not completely clear at the present time.
When performing physical exercises in conditions of high temperature, but low air humidity, the significance of heat transfer for sweat evaporation is exceptionally high. The maximum rate of sweating (up to 2 l / h in men is very high, so we can conclude that the efficiency of heat transfer from the body due to the evaporation of sweat is determined not so much by sweat production (this is not a "bottleneck"), but by its capabilities. evaporation. The rate of evaporation of sweat depends on 3 main conditions: skin temperature; water vapor pressure and air movement. If the body's heat output to the environment is insufficient, both the skin and internal body temperature increases. This increases the rate of evaporation, but at the same time increases the intensity of sweating. If sweating becomes very significant, most of the sweat flows off the body without evaporation, which does not lead to heat transfer and a decrease in body temperature. Since not all the sweat released evaporates, the efficiency of sweating as a heat transfer mechanism decrease. Sweating also turns out to be an ineffective mechanism if an athlete wears clothes, preventing the evaporation of sweat. If such clothing covers only certain parts of the body, then the skin temperature in these areas increases, which leads to local hyperactivity of the sweat glands of this area.
There are exceptionally large individual differences between people in their ability to produce a sufficient amount of sweat. Under standard conditions characterized by the same values of muscle work and thermal regime, it is observed that people acclimatized to work and living in conditions of high ambient temperature begin to sweat at lower temperatures /their "setting point" is shifted towards lower temperatures and produce sweat in larger quantities than non-climatized people. Trained athletes are usually characterized by less sweating than untrained athletes when performing work of the same absolute power.
Thus, there is a fairly visible relationship between physical training and acclimatization to work in conditions of high external temperature.