With such a concept as a “skin analyzer”, not all people came across. Most are used to calling it a shortened, more familiar term. That is skin. But, in fact, both of these concepts designate a complex organ, which is our outer cover. One of the few in our body that you can touch without any problems at any time. The skin area of an adult is approximately 1.5 - 2.3 square meters. And the mass, together with hypodermis (the integument deeper than the surface), is 16-17% of body weight. However, all this should be described in more detail.
Epidermis
First of all, talking about the skin analyzer, it is necessary to touch the epidermis. He is our outer layer. But this is in simple terms. In fact, the epidermis is a multilayer derivative of the epithelium. In thick skin that is not covered with hair, it includes as many as 5 layers. Each of them is located above the dermis. And they all have a barrier function.
An important nuance: the epidermis is characterized by constant updating. And this specificity is associated with the migration and transformation of the so-called keratinocytes. These are epithelial tissue cells. Their filaments are represented by keratin protein. In addition to this, it is also important to know that the epidermis contains certain components of the immune system.
The structure of the epidermis
The anatomy of the skin is very complex. Only the epidermis (one of its constituents) includes five different layers. The first is basal. Or, as it is also called, sprout. What is really important to know about the basal layer is that it contains the so-called melanosomes. These are melanin granules that protect us from the effects of UV rays.
The second layer is called prickly. It also includes a mass of cells, but the tonofibrillary apparatus can be considered the most important “brick”. It is the protection of the cell nucleus from mechanical damage.
There is still a granular layer. Consisting of 1-2 rows of elongated cells. It is in this layer that filagrin and keratolinin (structural proteins) are synthesized. And they contribute to keratinization of the epithelium. This, by the way, is the most complicated process, thanks to which the horny skin words acquire its characteristic elasticity and strength.
The fourth layer is known as cyclic (or shiny). In its cells there are neither organelles nor nuclei. And it looks like a shiny pinkish streak. This layer is well developed on the soles and palms.
And the last one is horny. This is a skin that performs a protective function. There are no living cells in it. Which is not surprising, because it is formed by dead keratinocytes. Or, as they are also called, horny scales. How thick this layer is depends on the loads exerted on this skin.
Dermis
This is the next thing that needs to be noted when talking about the skin analyzer. Because the dermis is the skin itself. And if expressed in scientific language - its connective tissue part.
The dermis is located under the epidermis. But not directly, they are separated by a basement membrane. It is distinguished by an abundance of capillaries and fibers, so that the dermis is given support and trophic functions. It, like the epidermis, consists of several layers. True, from a smaller number - there are only three of them.
Components of the dermis
The anatomy of the skin is very complex, but it can be understood. There are only three layers, and the first one that deserves attention is the papillary. Why is he called that? Because this is the first layer, it is represented by “papillae” that penetrate the epidermis. It consists of dozens of "components". These are tissue basophils, macrophages and many other cells that contribute to the implementation of the protective function of our immune system.
The second layer is called mesh. It forms a dense fibrous connective tissue. Actually, this is the main part of the dermis. It is in the reticular layer that contains the most powerful collagen fibers that contribute to the support function.
The last layer is called hypodermis. It is also called subcutaneous fat. It is located directly under the dermis. And, as you can understand, based on the name, it is formed by adipose tissue. It is due to it that water and nutrients accumulate under the skin. In addition, hypodermis promotes thermoregulation.
Functions: protection and purification
So, what is a skin analyzer, clear. Now you can list the functions performed by him.
The first is protective. As already mentioned, the epidermis protects nerves, tissues and blood vessels from the direct influence of the external environment. The skin contains sebaceous glands. There are about 300,000 of them. And over the course of a month they produce an average of 500-800 grams of fat. It lubricates the surface of the skin, protecting it, thus, from various influences.
The second function is cleansing. Skin is prone to sweat. So it frees the body from substances that are unfavorable for the body, which got inside along with medicines or food. Interestingly, there are about 2 million sweat glands in the skin .
Regulation, nutrition and respiration
These are also the functions of the skin analyzer, which traditionally belong to the main ones.
So regulation. The skin cools the blood if the external temperature is lower than that inherent in the body. It has the opposite effect in the opposite case. If the temperature of the environment is very high, then the skin muscles become relaxed, as a result of which the vessels expand, and the heat transfer by the body increases. Blood flow is also accelerating. As a result - profuse sweat.
The performance of the nutrition function is also determined by the departments of the skin analyzer. It is through our cover that animals, as well as vegetable fats, penetrate into the body. Solutions and creams are absorbed due to their special structure. No wonder these cosmetic substances are often called "nutrients."
The respiratory function, in principle, is characterized by the same specificity. Due to the porous structure of the upper layer, 2% of carbon dioxide is released through the skin. Surely not everyone knows that in 24 hours our cover removes about 800 grams of water vapor!
Neural connections
Much has been said above about what constitutes human skin. Its structure and functions are of particular interest. And one cannot help but pay attention to the topic of nerves with which our “shell” is abundantly equipped.
To put it in an accessible language, then the skin is a large field strewn with receptors. They constantly, every second, perceive irritations of a different nature coming from the internal and external environment.
Nerve fibers and endings (both encapsulated and free) - this is what else includes human skin. Their structure and functions are specific. The nervous system is located in the epidermis and dermis. In the hypodermis there are practically none. Only nerve trunks penetrate into it, forming a plexus there, from which the fibers extend into the dermis. From there, to the hair sacs, muscles, vessels, and sweat glands.
Nerve endings have their own names. For example, thanks to Krause flasks, the skin feels cold. And Meissner bodies contribute to the perception of touch. Due to Ruffini's bodies, we feel warm. You can list for a long time. But the most interesting thing is that there are about 200 pain, 2 thermal, 12 cold and 20 tactile receptors per square centimeter of skin.
Blood
Naturally, the structure of the skin analyzer is of particular specificity, due to which blood circulation is carried out.
So, in the hypodermis, in addition to nerve fibers and endings, there are large vessels. There are even arteries. They originate from the so-called arterial network, located directly above the fascia. They were mentioned at the very beginning.
From there, the arterial network spreads further - into the deeper parts of the reticular layer. And from there - straight to the papillary.
It is important to know that in the skin layers there are not only capillaries and venules, but also arterioles. Which are directly involved in the regulation of OPSS (total peripheral vascular resistance). The tone of the arterioles is extremely important. After all, peripheral resistance depends on it, which determines blood pressure. This is the characteristic of a skin analyzer. However, she is not surprised. After all, we are talking about a single, integral organism, in which absolutely everything is interconnected.
Sensitivity
This topic is also worth noting attention. There is such a thing as musculocutaneous sensitivity. Its origin is clear. After all, often they exert an effect on the muscles by touching the skin first. Take, for example, the same massage.
But skin sensitivity is special. It is composed of various analyzers. Touch, for example, is a complex feeling that results from feeling objects. Tactile sensations play an important role here. Analyzers that sense pressure and touch give us information about the density of an object, its shape, temperature, condition, size and much more. Especially many receptors are concentrated on the fingertips. It is from them that the "path" of information signals transmitted to the brain begins.
Regeneration
It is of two types. The first is called physiological. A completely normal, natural process involving cell renewal. Its course depends on nutrition, physical health and human immunity. This, in turn, affects the appearance and youth of the skin.
And reparative regeneration involves the restoration of the cover after mechanical damage. After surgery, for example. The process is very interesting. First, the phase of inflammation occurs - bleeding stops, swelling occurs, which presses on the nerve endings and causes pain. Then proliferation begins. The wound is filled with capillaries and connective tissue - thereby collagen. The last phase involves the formation of a scar. This process ends with filling the lesion with epithelial tissue.
Some scars may form a year. And while the skin is characterized by regeneration, the damage does not pass without a trace. Therefore, you need to be careful.
Interesting Facts
They should finish the story about what constitutes musculocutaneous sensitivity (we also examined the structure of the analyzer and its functions). Indeed, there are several interesting facts, and here are some of them that deserve attention:
- It is hard to imagine, on the entire surface of our skin there are about five million hairs!
- In an adult, the skin is 60% moisture. In children - by 90% (but this is the maximum).
- For every square centimeter of skin, there are 100 pores.
- On average, the cover reaches 1-2 millimeters in thickness.
- The coarsest leather on the soles. The most delicate and transparent - for centuries.
- Throughout life, about 18 kilograms of keratinized skin is replaced by a new one.
Well, much more can be told interesting about our cover, its structure and specific features. But the basic principles of anatomy were listed above, and it is useful for everyone to remember them, since this topic concerns us all directly.