The skin is an organ with a very complex structure. Its area in an adult varies from 1.5 to 2 m. In different parts of the body, it has a different thickness – from 0.1 to 4 mm. The skin covering the back, skull, hips, feet and palms has the largest thickness (about 4 mm), and the skin of the eyelids is 10 times thinner (0.4 mm).
There are three main layers:
• cuticle , or epidermis,
• the skin itself, or dermis,
• subcutaneous fat, or hypodermis.
The stratum corneum of the cuticle is the most superficial and consists of thin horn cells covering the entire surface of the skin. The cells of this layer constantly peel and fall off. This process of physiological rejection of obsolete cells occurs when washing, wiping the skin. It proceeds slowly and in a healthy person remains almost invisible. The growth of new cells occurs in the inner, germinal layer of the cuticle .
The skin itself consists of thin connective tissue and special elastic fibers, which determine its firmness and elasticity. In the structure of the fibrous structures of the skin itself, age-related changes in the human body are clearly reflected.
Subcutaneous adipose tissue binds the dermis to the underlying organs.
The condition and basic functions of the skin depend on many factors, both internal and external environment. The skin is closely connected with the body through the nervous, circulatory and lymphatic systems. Therefore, any disease of the internal organs, nervous system, etc. affects it.
At the same time, skin damage can lead to reciprocal changes in organs and systems.
Skin as a protective organ.
The epidermal layer of the skin protects the nerves, blood vessels and tissues located beneath it from the harmful effects of the environment. By producing pigment, the skin protects the body from excessive exposure to sunlight.
Sebum, lubricating with a thin layer the surface of the skin and hair, protects them from the harmful effects of water, sweat and various chemical compounds – acids and alkalis, which have to come into contact in everyday life. There are about 300,000 sebaceous glands in human skin. Most of them are on the scalp, on the face, back and chest. Normally functioning sebaceous glands secrete within a week from 100 to 200 g of sebum.
Skin as a cleansing organ.
The skin, releasing sweat, frees the body from a number of metabolic products harmful to it, which accumulate in the blood and tissues (urea, ammonia, etc.). Along with then, various toxic substances that enter the body from the outside are also released.
Human skin contains more than 2 million sweat glands, which are distributed unevenly throughout the body. Usually a healthy person gives out from 0.4 to 2 liters of sweat per day.
Skin as a regulatory body.
The skin takes an active part in the thermoregulation of the body, ensuring a constant body temperature both in summer and in winter. At elevated external temperatures, the skin muscles relax, the vessels expand, the blood flow and the body give off heat: there is abundant sweat.
At a low temperature, the vessels of the skin narrow, the blood flow decreases, the heat transfer decreases sharply. It should also be noted that both sweating and heat regulation are carried out under the constant control of the central nervous system.
Skin as an organ of nutrition.
Animals, vegetable fats, etc. are absorbed through the skin by the body. This property is taken into account in cosmetics when preparing various solutions and creams, which include medicinal substances, vitamins, hormones, and other products that penetrate the skin.
Skin as a respiratory organ.
The respiratory function of the skin is the exchange of gases. Approximately 2% of the carbon dioxide secreted by the lungs per day is released through the skin, and about 1% of all respirable oxygen is absorbed. In addition, the skin removes up to 800 g of water vapor per day, exceeding in this respect the work of the lungs by more than two times. The diverse functions of the skin determine its important role in the life of the body.
Skin is a mirror of health.
If they say that the eyes are a mirror of the soul, then the skin is a mirror of health. Each of us has repeatedly noted in everyday life that various emotions, especially negative ones – irritation, ill health, etc., quickly reflect on the external appearance of a person, and especially on the skin of the face.
Sometimes such adverse factors are reflected on the skin of the body. For example, sweating, itching of the skin can occur as a result of neuropsychic influences. That is why it is a deeply erroneous opinion that only the use of cosmetics can eliminate skin defects, without regard to the general condition of the body, and in particular the nervous system.
The most common diseases that occur in women of various ages and adversely affect their appearance include the following: diseases of the gastrointestinal tract (constipation); violations of the function of the endocrine glands (menstrual irregularities, thyroid disease) ; vitamin deficiency (lack or extremely insufficient intake of vitamins in the body), etc. Violation of the vitamin balance in the body, directly affecting the condition of the skin, is reflected, in addition, on the general condition of the body causing, in particular, depressed mood, increased irritability, and decreased ability to work.
Thus, we must not forget about the relationship of the central nervous system, internal organs and skin. Our skin, as the most sensitive barometer, reflects both our health and ill health. The correct mode of work and rest, nutritious and regular nutrition, playing sports, maintaining a good state of health, are favorably reflected in the appearance of a person. And vice versa – insufficient nutrition (dictated by the desire to lose weight) leads to the development of diseases, which inevitably worsens the condition of the skin – causes peeling, irritation, dryness, etc.