The skin we live in. Part 2

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Our last article talked about the human skin and what functions it performs in our body. Today we discuss the structure of this unique body organ in further detail.

Why bother to get into these unchartered waters of human anatomy and grind away at cosmetic studies? Well, the response is obvious, dear friends. Knowledge is the power, and knowledge of the nature of our own body is the key to understanding the mechanisms that control the regeneration and recovery processes of natural resources. Everyone should study the principles of work performance in the skin, at least in general terms. It is the way we can save the treasure given to us by nature. Alas, customers can easily fall for the tricks of cosmetics manufacturers and beauty centers. It is increasingly evident that using the cult of "instant beauty", they often pursue the only goal, their profits. Let's learn together and evolve from the level of the ordinary consumer to the story of a prudent and informed buyer, avoiding glorified and merchandized yet another "magic lotion made of pink unicorn mane". A load of responsibility for our health rests on our shoulders.

Our skin is the outpost that protects us from the misery of the environment. How is it arranged?

Human skin is a very complex organ. It consists of three layers: epidermis, dermis, and subcutaneous fat. It has one more face layer, which is not related to the skin formally, but it plays a vital role in cosmetics and interpersonal communication. This layer is called facial muscles.

All these layers constitute the various kinds of tissues: epithelium, connective and adipose tissues. Each layer contains a large number of cells. In the dermis, there are differentiated (i.e., having specialization and working in the body on its own "service instructions"), and the so-called stem cells, undifferentiated and capable of developing into different cell types under certain circumstances.

Another unique feature of the skin is that it employs living cells, intercellular substance (a kind of "gel" that fills the space between the cells), and dead cells (horny scales) in a friendly alliance. Therefore, in cosmetology, you can achieve a positive effect by playing on two fronts at once: by acting on the "tactical and technical characteristics" of inanimate matter, that is, on the upper stratum corneum and intercellular substance, or by working with living cells of the deep layers and achieving slow but stable positive rearrangements in their work. Each cosmetic product or therapeutic method has its own "target effects" in the skin structure, so our goal is to understand the mechanisms of their work, whether it is homemade scrub or serious and expensive course of therapeutic procedures.

Let's arm ourselves with an imaginary microscope and examine each layer of the skin in more detail.

Epidermis

The epidermis is mainly composed of a single cell type called keratinocytes. The bottom of the epidermis is called the basal membrane, and on the surface, there is the horn layer. This uppermost layer of the skin constantly regenerates because it was the first to assume the aggressive beats of the environment. Keratinocytes, being born in the basement membrane, gradually move up and take the place of overage cells. That happens so smoothly and orderly that within the epidermis, it's able to distinguish the individual layers of keratinocytes in various stages of development or maturation. In their movement from the basal membrane to the surface, living cells gradually die and lose their nuclei. After reaching the top layer, these dead cells - now called by a different name, corneocytes - from the stratum corneum or horny layer. That is the same microscopically thin film that forms the blister in mild burns or abrasions. The cells of the horny layer under a microscope look like a mosaic of tightly interlinked hexagonal plates. The lipid barrier of the skin holds the individual parts of this mosaic together and ensures the integrity and strength of the stratum corneum. The corneocytes, these translucent flakes perform the same function as the bird's feathers or lizard scales: they protect our internal environment.

Thousands of dead flakes get lost from the skin surface every minute and get into the surrounding atmosphere. Those tiny airborne specks of dust that we can see in the beam of bright light are 90% skin particles.

The basement membrane, which connects the epidermis and dermis, is a thin plate. It contains:
- germ cells;
- stem (undifferentiated) cells;
- Largenhans cells - "security", preventing the penetration of harmful substances and organisms into the dermis;
- Merkel receptor cells - "hormone factories", responsible, in particular, for the production of endorphins.
It also serves as an additional filter, limiting the penetration of foreign substances into the dermis. The basement membrane is easy enough to damage; for example, during deep peeling procedures, some complications such as scarring can occur. Fortunately, nature has provided additional safety measures: this membrane is heterogeneous in its structure and has depressions and protrusions. Therefore, with superficial skin injuries, it is damaged only in certain areas with the possibility of further recovery.

Dermis

This layer is responsible for the elasticity and strength of the skin. Can compare dermis in its structure with elastic mattress, which rests on the epidermis. It is laced with longitudinal and transverse "springs" - collagen and elastin fibers. The space between them is filled with a unique gel-like substance, composed essentially of hyaluronic acid. The critical property of hyaluronic acid is the ability to bind water. The structure of its molecules resembles a fishing net with many meshes, which capture the water molecules and turn them into a viscous gel. Each "net" can hold between 200 and 500 water molecules. This entire "catch" of the water is used by the body to synthesize new cells and output the decay products and toxins. Skin regeneration is a continuous process, and, like in any industry, water plays a key role.

The skin elasticity and its resistance to the physical impacts directly depend on how much collagen, elastin, and hyaluronic acid.

The role of "mid-level managers", responsible for synthesizing these elements, is performed by connective tissue cells called fibroblasts. These cells monitor the production of new components of the dermis and the well-time destruction and disposal of worn-out parts. Research figures that with age, the activity of fibroblasts decreases, and the synthesis of new materials for dermis results slower than its destruction. Therefore, the skin does not have enough time to get recovered and starts to age.

Blood and lymphatic capillaries and vessels play the role of the transportation system, which supplies oxygen and all the necessary components to the dermis, and removes the waste products of metabolism. The epidermis doesn't have its blood-circulatory system, so the condition of the top layer depends on "delivery" from the dermis. To maintain the intensity of the blood flow in the dermis and, thereby, preserve the beauty of the skin, you need to perform treatments that strengthen the walls of blood vessels and improve blood circulation. These health precautions include physical conditioning exercises, facial gymnastics, contrast shower, massage, and use of natural cosmetics that contain rosemary, geranium, neroli, chamomile, lemongrass, calendula, etc.

Therefore, although the dermal layer and not visible from the outside, keeping it in good shape is the key to radiant skin and a healthy complexion.

Subcutaneous fat

This soft lining, located directly beneath the dermal layer, is composed entirely of fat (adipocytes) and designed for thermal insulation of the body and damping mechanical injuries. It accumulates fat-soluble vitamins of groups A, D, E, and estrogen hormones. Adipose tissue has an extensive network of blood vessels designed to instant control fat levels in the blood. Pathologies caused by unhealthy lifestyle and nutrition, such as excess fat in cells, thickening of the septa between fat lobules, swelling, inflammation, and others, may negatively affect the skin's beauty and overall health.

Facial muscles

There are 57 facial muscles. One end of each muscle is fixed to the cranial bones, and the other end – to the face skin or the surrounding muscles. When the muscle is contracted, it pulls the skin, causing facial expression changes: puckering of the eyebrows, forehead wrinkling, lips stretch into a smile, etc. Folds in areas of active facial expressions result from tension and displacement of the skin during muscle contraction.

There are 57 facial muscles. One end of each muscle is fixed to the cranial bones, and the other end – to the face skin or the surrounding muscles. When the muscle is contracted, it pulls the skin, causing facial expression changes: puckering of the eyebrows, forehead wrinkling, lips stretch into a smile, etc. The only exceptions are the mastication muscles, which, like the body muscles, are attached to both ends of the bones.

A human face (and the body) visually looks old if the muscular system loses its tone and begins to "sag". Skin folds in the active zones are the result of the tension of the skin during muscle contraction. While an organism is young, such dislocations do not form skin defects, as its renewability is much higher than the speed of decomposing its structural proteins (collagen and elastin).

While the body is young, such displacements do not lead to the formation of skin defects since its ability to regenerate is much higher than the rate of destruction of its structural proteins (collagen and elastin). Over time, the synthesis of collagen and elastin becomes less intense, and their destruction becomes more and more significant. In turn, the face and neck muscles are deformed, being in constant hypertonicity. As a result, wrinkles appear in these areas. However, the muscles of both the face and the body are amenable to training, becoming more elastic and robust. Regular facial gymnastics tightens the muscles, allowing for positive visual changes without surgery or injections. Simple but highly effective exercises for the facial muscles combined with natural cosmetics give a long-lasting and lasting result without surgeons' toxic injections and scalpels.