The skin covers the body of a person from the outside, sheprovides protection of all internal organs from external influences (friction, pressure, shock, rupture). In addition, the cover prevents the penetration of various bacteria into the body. Its thickness varies from 0.5 to 4 millimeters in various parts, the approximate mass is 3 kilograms.
The structure of the skin allows it to participate inexchange, excretory and protective processes, as well as thermoregulation of the body (temperature regulation). During the day, about 500 milliliters of water are released through the cover. This is 1% of the total body volume. The structure of the skin involves the removal of protein metabolism products and various salts. The cover absorbs oxygen, releasing carbon dioxide. Mineral, water and gas exchange of the cover in intensity is only slightly inferior to the intensity of metabolism in the muscles and liver.
The structure of the human skin allows performingsignal function-it is provided by a large number of sensitive receptors located in all its layers. With the help of them, people are able to perceive pain, pressure, heat, touch. The structure of the skin allows you to be located in separate areas in 1 square. see up to twelve cold, two hundred painful, two thermal and twenty-five reactive endings. It should be noted that the presence of sensitivity performs the most important task for the interaction of the body and the environment, prevents burns, injuries, frostbite.
Leather. Structure.
Normal functioning of the bodypresence of permanent conditions for existence. External factors are quite variable and have a permanent impact on a person. Ensuring and preserving the integrity of the whole body lies on the outer veil of the body. The structure of the skin is quite difficult. This body is represented by three layers.
The uppermost is the epidermis.It has a thickness of 0.03 to 1.5 millimeters and more (for example, on the sole or palms). It, in turn, consists of five layers. The superficial layer (horny) is represented by dead keratinized cells, closely adjacent to each other. They are constantly being separated and replaced with new cells. The epidermis performs the function of protection. It is he who prevents the influence of external factors on the body. Due to its structure, the epidermis has elasticity, strength and elasticity. In addition, it is able to recover quickly enough with minor damages. Each of its five layers ripens one into another, so there is a constant update. Completely the cells are renewed for 26-28 days. Their all organs only skin cells are able to multiply and grow at such a speed.
The next layer of the outer polka - dermis -is represented by interwoven fibers. The main ones are collagen and elastin (collagen and elastin are the main structural skin proteins). Due to them, the cover has elasticity, it is able to restore its original state after stretching. In the dermis, two layers are distinguished. Lymphatic and blood vessels, muscles, nerve endings, sebaceous and sweat glands, hair pass through a deep layer.
Under the dermis is located subcutaneous fatcellulose (hypodermis). This layer is a kind of "pillow". Its thickness varies, depending on the site of the body. This is due to the roundness of body shapes. The hypodermis protects the body from hypothermia, injuries, external irritants, is a storage layer where fat stores are stored, consumed in case of illness, pregnancy, hunger.
Practically on each site of a skin are locatedsweat glands. Most of them on the pads of the fingers and toes, soles, palms, in the inguinal and axillary folds. These glands are involved in the excretory function.
Sebum is a secret secreted by the sebaceous glands. It makes the skin supple, softens it.
