What does the skin do

The skin has physiological functions such as protection, sensation, regulation of body temperature, absorption, secretion and excretion, and metabolism. In this article, we will mainly introduce the seven physiological functions of the skin.

Protective functions

The skin covers the surface of the body, and the epidermal layers of cells are closely connected. The dermis contains a large number of collagen fibers and elastic fibers, making the skin both tough and soft, with a certain degree of tensile and elastic. When rubbed or pulled by external forces, it can still remain intact and recover its original state after external forces are removed. The subcutaneous tissue is loose, contains a large number of fat cells, and has a cushioning effect. The skin can block electric currents. The stratum corneum of the skin is a poor conductor and has a certain insulating ability against electric currents, which can prevent a certain amount of electric currents from harming the body. The stratum corneum and melanin granules of the skin reflect and absorb some of the ultraviolet rays, preventing them from entering the body and harming internal tissues. The sebaceous glands secrete sebum and the sweat glands secrete sweat, which mixes to form an emulsified skin film on the surface of the skin, which moisturizes the stratum corneum and prevents the skin from drying out. Sweat protects the skin by diluting the acidity of chemicals to some extent. The sebaceous film on the surface of the skin is weakly acidic, which can prevent the invasion of bacteria and fungi on the surface of the skin, and has antibacterial and antiseptic effects.

Sensory function

The skin contains many nerve endings, which are distributed in the epidermis, dermis and subcutaneous tissues, so that we have "pain, touch, cold, heat, pressure, itch" and other sensations. Do not underestimate these sensations when environmental changes or external stimuli on the body to produce adverse effects, these sensations are like the body's early warning mechanism, timely remind us to take measures to prevent various violations. With the help of the sensory role of the skin, and with the other sensory organs, human beings can carry out a normal life.

Regulation of body temperature

Body temperature is a manifestation of the heat generated during the metabolism of substances in the body, and is one of the essential conditions for the cells of the body to carry out various biochemical reactions and physiological activities. Regulation of body temperature is one of the important functions of the skin. The skin is an important component of the body's heat distribution and can regulate body temperature in the form of skin vasoconstriction, hair standing and reduced sweating, as well as through physical means such as radiation, convection, conduction and evaporation.

Secretion and excretion

The small sweat glands of the skin have the function of secreting and excreting sweat. Sweat is mixed with sebum after excretion. It forms a milky lipid film. It can make the stratum corneum soft and moist and prevent dryness and cracking. Sweat makes the skin somewhat acidic. It can play the role of inhibiting the growth of bacteria. The sebaceous glands can secrete sebum, and when the ambient temperature rises, the sebum's sorrowful consistency decreases and is more easily discharged from the mouth of the hair follicle, where it mixes with sweat to form a milky sebum film, which plays a role in protecting the skin.

Absorption function

The skin is the outermost protective barrier of the organism, preventing water and certain chemicals from entering the organism and absorbing substances that are useful or harmful to the organism. The main route of skin absorption is through the cell membrane of the stratum corneum. It can also be absorbed through hair follicles, sebaceous glands and sweat ducts.

Metabolism

The formation of various tissue components of the skin and their physiological functions require certain biochemical metabolic processes to be completed. ①Water: The water in the skin is mainly in the dermis, and the daily water emitted from the skin is about 500 ml. When there is inflammation in the skin, the evaporation of water increases significantly. ②Electrolytes: The electrolytes in the skin are most abundant in sodium chloride and potassium chloride. They also include magnesium, calcium, copper, phosphorus, sulfur, zinc, etc., each with its own different physiological role. (7) Glucose metabolism: sugar provides energy for cellular activity. The glucose content of normal epidermis is about 2/3 of that of blood glucose. Diabetic patients have increased glucose content in the skin, so they are susceptible to bacterial and fungal infections. In addition, there are various metabolic functions in the skin such as protein metabolism and fat metabolism. The metabolic function of the skin is most active from 10pm to 2am, so a good night's sleep during this period is beneficial for skin care.

Immune function

In addition to its non-specific barrier function, the skin is also a very important immune organ. When external substances come into contact with or enter the skin, some cells in the skin with special functions will recognize, transmit information and memory to them or produce phagocytosis and rejection of antiqing, and some special cell components, cell gonads, immunoglobulins and complement in the body, all these reactions are collectively called immune response, which is not only a self-protection mechanism of the body, but also the basic cause of many skin diseases. It is both a self-protective mechanism and the basic cause of many skin diseases.