Why can people still maintain normal body temperature in cold environments?

This starts with the internal environment of the human body. There are many ways to maintain the balance of the human body, such as the balance of inorganic salts, body temperature balance, immune system balance, etc., and when it comes to human Constant temperature is due to the regulation of body temperature in the internal environment, and is maintained by nerve regulation and body fluid regulation. When the weather is hot, the body temperature does not rise too high because of nerve regulation, and its heat dissipation method is piloerection. Muscles relax, increase perspiration to dissipate heat, blood vessel walls relax, increase bleeding volume, to dissipate heat, etc. As for the cold environment that the questioner asked about still maintaining body temperature, it is the effect of nerve regulation and body fluid regulation. Body fluid regulation involves increased adrenaline secretion. Increasing the excitability of the nervous system will also increase the secretion of thyroid hormones, but this also involves neural regulation, that is, the secretion of thyroid hormones consists of neural regulation and humoral regulation. There are temperature receptors on the human body surface, internal organs and other places. When it is cold, the cold receptors on the body surface are stimulated and conduct excitement to the hypothalamus. There is a temperature regulation center here, which sends out signals to stimulate the release of hormones, thereby regulating the rate of metabolism. , increasing heat production; in addition, there are a series of contraction reactions of skeletal muscles (commonly known as shivering), and the arrector pili muscles on the skin surface also contract, reducing heat dissipation. That is, the body's temperature regulation system reduces heat dissipation. Increase thermogenesis to achieve body temperature balance. In fact, in short, it is the balanced relationship between heat dissipation and heat production. When it is cold, the body's steady state will dissipate less heat and produce more heat; when it is hot, the reverse is true.

The most essential thing is to thank evolution for its benefits, which allow humans to have the most sophisticated body regulation system!