The importance of skin for the human body

Skin appears to be the most complex and most voluminous organ of a person. In our life it plays a crucial role, and therefore is the main structural element of the body. Providing protection, maintaining heat and water balance, it supports life in the conditions in which a person resides. And, of course, this is not the only skin value for the body. She still has many functions, which should be thoroughly understood. This requires a basic examination of the structure of the skin and its cellular composition, the mechanisms of functioning.

Basic skin function overview

Among the numerous functions of the body, many can be realized only with the presence of skin. If we consider it from the phylogenetic point of view, it is obvious that it was created to save the liquid in the body. It was necessary for the organisms to settle the land. Moreover, in the phylogeny, the skin appeared much later than the scales and shell, considerably exceeding them by the flexibility of adaptation to the surrounding conditions, but still performing the basic functions. Among them:

• Regulation of body temperature;

• Protective (barrier);

• Regulatory (participation in water-electrolyte exchange);

• Cumulative (serves as the place of deposition of blood);

• Metabolic and endocrine;

• Receptor;

• Immune;

• Excretory.

The above functions are very important, because they support the functioning of organ systems. And this is the skin's importance for the body: it is responsible for interacting with the environment, but at the same time it protects from its harmful effects. It removes liquid from the body, but simultaneously "watches" for its temperature, so that more is not removed than it should. In some organisms, the skin also participates in the exchange of gases, playing the role of additional lungs. In humans, this function - due to the complex structure of its respiratory organs - is lost.

Structural features of the skin

In the educational and methodical complex "We and the World" in the section "The Importance of Skin for the Organism" (4th class) contains information on its structure. The materials for this training manual were taken from books on histology and physiology of the skin. They provide more detailed information on the structure of the outer cover of the body, the cells involved in its formation, and their functions.

The morphology of the skin is represented by three layers: epidermis (upper layer), dermis (mesh and papillary layer) and fatty tissue. The latter is located most deeply. These three layers form our veil. In the subcutaneous tissue develops fat tissue, performing metabolic function.

In the dermis are located the growth zones of the skin, blood vessels, as well as nerve endings (receptors). The latter are able to recognize the physical characteristics of the medium with which they contact. Also in the dermis are the terminal sections of sweat glands and hair, equipped with a fat bag.

The epidermis is the least active part, because it performs only a protective function. However, the skin value for the body is great and thanks to it, because without protection, the human body would instantly be exposed to various influences, including physical, biological and chemical factors. Even a simple temperature, or rather, its oscillation within 10 degrees, could destroy us if it were not for the presence of multi-layered epidermis.

The role of skin in thermoregulation

The main importance of the skin in the process of thermoregulation is difficult to challenge. It is this organ that has thermoreceptors, through which it can determine the approximate ambient temperature. Based on this information, the body temperature control process takes place . In a situation where the parameters of the environment exceed the body, the body includes the processes of sweating and dilating the loop vessels of the skin. Due to this, it cools, and existence under such conditions becomes more comfortable.

In a situation where the temperature outside the body is lower, the skin determines this by using the cold receptors. They are approximately 5-6 times greater than the thermal receptors. Then the process of reducing heat loss is started by narrowing the vessels and reducing the skin surface (goosebumps). In addition, processes of lipid cleavage in the cellulose are intensified, which makes it possible to produce some heat for warming and maintaining the life support of the body.

Protective function

However, thermoregulation is not the only skin value for the human body. No less important is the protection not only of heat and cold, but also of other factors of chemical, biological and physical nature. The main role in the implementation of the barrier (protective) function belongs to the epidermis. Its lipophilic structure limits the percutaneous intake of substances that can dissolve in water.

Also, the layer of epidermal cells protects against mechanical factors - squeezing, piercing, cutting. The epidermis is much harder than the dermis and fiber, and therefore any of these effects would lead to serious damage, without this layer on the surface.

Equally important is the protection from ionizing radiation, at least from longwave with medium and low frequency. In particular, the skin protects well from ultraviolet radiation, although it can not protect the body from gamma rays from X-rays. It is not surprising, because the latter are able to penetrate and through the concrete walls. But even the presence of protection against neutron radiation, from alpha particles and from ultraviolet significantly prolongs a person's life.

And since not only physical factors are capable of killing our body, it must develop protection against biological aggressors. They are saprophytic bacteria, viruses, fungi and protists. Of all of them, only fungi can penetrate and colonize its thickness through the skin. And only because their mycelium branches and falls into the gaps between the epidermal scales, lingering in them. But from the bacteria and viruses the epidermis reliably defends the body, and this skin value for the human body briefly characterizes all the processes of its adaptation to environmental factors.

Water-electrolyte regulation

The great importance of the skin for the body is also in the regulation of the water-electrolyte balance. What is achieved by removing sodium, water and chloride ions together with sweat. Also with this liquid are removed and some toxic substances of acid nature. This creates interesting opportunities for the body, which is cooled by its own liquid.

The physical essence of the process of evaporation is this: first, through the sweat gland, water is released to the outside. From the surface of the skin sweat evaporates, thereby cooling it. In this case evaporation leads to loss of kinetic energy of water molecules. As a result, the skin temperature is somewhat reduced. By the way, this biological process is not effective for cooling the body in situations where the environment is hot (for example, in a bath).

Function of blood deposition

One of the widest and most complex vascular networks is located in the dermis. There are only three of them: two arterial and one venous. Moreover, in the skin there are wide capillaries in which blood can be retained. This allows you to accumulate some of it in order to release and return to the bloodstream for gas exchange during the physiological reaction of stress.

In total, up to 15% of the total blood volume can accumulate in the skin of the skin at a time, which constantly changes to prevent slugging and thrombosis. As soon as the humoral signal comes in that it is required to expand the arterioles of the body and set it in motion because of the above-threshold stress, the blood will return from the capillaries to the systemic bloodstream. The organism as a result of this will add to the endurance and strength. And since it often saves a life in case of danger, the skin value for the human body in this respect is simply enormous.

Endocrine and metabolic functions

Subcutaneous fat is the body of fat accumulation. The latter is spent sparingly to provide reserve energy needs. It is from cellulose fat is taken by the body in the last turn, so it is so difficult to lose weight. However, now this skin value for a person is not the main thing. Much more important is the endocrine function, namely the regulation of hunger and satiety.

The fat tissue of the subcutaneous tissue is a powerful gland capable of releasing substances that regulate saturation. And about the feeling of hunger "reports" the level of glucose in the blood. As soon as it falls, there is a famine. As it saturates, it is inhibited by hormones from adipose tissue that "talk" about the fact that you should not eat more.

Receptor function of the skin

Discussing the topic "The importance of skin for the body" (grade 4 of the school studies it), it is impossible to ignore the receptor function. It is one of the most important, because it allows you to obtain information about the habitat. The skin through the receptors determines the temperature of the environment, the density of certain objects, humidity, surface texture and other morphological parameters.

Even pain receptors are located in the skin, which protects us from getting large damages. And it is pain that is the "guard dog" of human health.

Excretory function of the skin

The skin due to the presence of sweat glands is able to excrete metabolic products. As a rule, these are high molecular weight lipophilic substances or hydrophilic small molecules with acid reaction. The first are proteins and fats, necessary for hair treatment, the bulb of which opens the duct of the sebaceous gland.

The second substances (low molecular weight) get here directly from the blood and come to the surface with sweat. It is noteworthy that the excretory function of the skin visually represents such a disease as gout. When it develops in the blood, the amount of uric acid increases substantially , which is later discharged through the skin in the form of crystals.

Another example, unfortunately, is imperfect. It is associated with an attempt at excretion of bile acids in parenchymal lesions of the liver. However, all the same, this skin value for the vital activity of the body is extremely large, because it helps to regulate the exchange of toxic and harmful substances. And this is one of the mechanisms of human life support.

Immune function

Agree, the importance of skin for the human body is great. Pictures on the subject, attached as a visual material, demonstrate the complex structure of our outer cover. It is difficult to imagine, but there are also immune reactions that are important for the protection of the whole organism. And the protection is not from external enemies and factors, but from pathogens trapped in the internal environment. And this function is realized by means of neutrophils, monocytes, macrophages and lymphocytes.

Also in the skin there are Langerhans cells and basophils. They regulate local defenses of immunity and participate in the presentation of antigens to plasmocytes. It is noteworthy that the immune function of the skin is mediated and another important mechanism that should be considered metabolic. Our outer cover is the site of the synthesis of the pro-vitamin D. important for the development of immunity and the human skeleton.

In the future, he will pass the stage of treatment in the kidneys and will perform his function. However, the place of its formation is the skin. Here, under the influence of ultraviolet light, a small amount of which the skin nevertheless gently passes through itself, this substance is born. And its importance for the development of the skeleton is enormous. And the role of skin for the whole organism is even greater.