Body temperature is an important indicator of human health
Body temperature is a very important indicator,characterizing the state of human health, because it is often the first sign of an evolving problem. If its value is normal, then we are talking about the normothermy. Increase is hyperthermia, and hypothermia is a reduced body temperature. The normal temperature for measurement in the armpit is in the range of 36 to 36.9 ° C. However, not all so simple.
The temperature of the human body differs in itsinternal and external layers. The organs and the brain are conventionally referred to as internal organs. The temperature of the "core" is constant. And it is she who is of clinical importance. It is measured in the following places: rectum, oral cavity, axillary fossa. But it is worthwhile to know that the value of the temperature when measuring in the mouth (oral temperature) is 0.2-0.5 degrees below the rectal temperature, in addition, the axillary values (axillary fossa) are 0.5-0.8 degrees below the temperature in the rectum . A surface layer, or "shell," whose depth is 2.5 cm or more, is also isolated. The temperature here is very variable not only in different parts of the body, but also under different conditions of the external environment. In comfortable external conditions, the body temperature in the surface layers of a naked man is 33-34 ° C, while the temperature of the foot at this moment can be within 24-28 ° C. In general, this indicator is very variable. The constant body temperature can fluctuate during the day in the range of 0.5 to 1.5 ° C, but still fluctuations rarely exceed 1 ° C.
What mechanisms ensure the maintenance ofthe temperature of our body at a constant level? This is ensured by a harmonious relationship between the processes of heat production and heat transfer. Heat production can be contractile and non-reduced. The contractile mechanisms include voluntary and involuntary muscle contractions: muscle tone rises, there is a shiver, a person performs any physical exercises. The share of non-reduced thermogenesis can reach 70% in the cold. The source is a brown fatty tissue, the mass of which is 1-2% of the total body weight of a person. The mechanisms of such heat production are not clear enough, but they are supposed to be related to the fact that this tissue contains a lot of free fatty acids, during the oxidation of which it produces heat.
Now let's talk about the heat transfer process, whichIt is important to prevent overheating of the body. Gives the body heat as follows. Blood from the depths of the body carries heat to the surface, where the dilated blood vessels give it to the environment because of the hot weather. In addition, it is important to sweat and give the person the heat in the form of infrared radiation. Thus, it is due to the relationship between the processes of heat production and heat transfer that the temperature of the human body is maintained within normal limits.
An increase in body temperature above 37 ° C is calledhyperthermia. Common reasons for its development is an increase in the temperature of the external environment and a violation of the ratio of heat production and heat transfer, namely, the predominance of the former over the second. With the advent of contributing factors, mechanisms that anticipate a rise in temperature are included, which, unfortunately, is not always possible. A person is able to withstand a value of 43 degrees a fairly short time. Longer survival is possible at 42 degrees. But it is worthwhile to know that already at 40-41 degrees there are lesions of the brain, for example, its edema or the death of some neurons. About hypothermia is said when the body temperature is below 35 ° C. This may be due to the person being in the cold for a long time. First, heat production processes increase, and there is no harm to the body, but then they are gradually depleted, and a temperature drop occurs. If the recession reaches 31 degrees, then the person loses consciousness. At 24-28 degrees, death usually occurs.
