Know your skin - a bit of anatomy

Dec 6, 2022

To be able to take care of your skin, you have to know it. We talk all the time about the different types of skin, either oily, normal, dry or combination, but do we know what it is for, how it is made up and how does it evolve?

The role of the skin

The first role of the skin is to protect our body, and yes! It is first of all a barrier that protects us from external attacks such as pollution, the sun's rays, cold or heat, but also from scratches, blows and shocks. It is also the first bulwark against chemicals, viruses and bacteria.

It's already impressive, but its role does not stop there. It plays an essential role in regulating our temperature, it provides a multitude of information on the sensations and relationships with the outside world, and it also transmits information to the outside about our own state of health, our way of life and our state. emotional.

Structure of the skin

First of all, the skin is the most voluminous organ of the human body, it can reach a surface of 2m2. It is made up of three main layers: the epidermis, the dermis and the hypodermis.

The epidermis

The first layer, called the epidermis, is made up of several sub-layers which create epidermal renewal. It is the renewal of the skin, a very important process, which takes between 3 and 4 weeks. At the base of the epidermis, there is the basal layer. At this level, there is a cell division which expels a cell upwards. When cells rise, they transform. First, they flatten and load up with Keratin . Then, they harden and bridges are created between the cells. Then, the cell dies, it loses its nuclei (this is the stratum corneum). The cells of the stratum corneum are bound together by epidermal lipids. These lipids are essential to the health of the skin because they create its protective barrier and have a water-retaining power. Eventually, they come apart. Every day we shed two layers of dead cells.

Let's not forget that the epidermis is dotted with holes, called pores, from which sweat comes out. The epidermis also contains melanin, responsible for our skin color. There is red and brown melanin. Melanin is produced by melanocytes and are there to protect our skin from the sun's rays.

The dermis

In the dermis, there are many corpuscles that perceive temperature, pain, and touch. There are also the hair follicles, which come out through the pores. There are also small (sebaceous) glands that produce sebum, as well as sweat glands.

The dermis is thicker than the epidermis, made up of collagen , elastin and connective tissue. It is the dermis that gives the skin its elasticity and suppleness, in particular thanks to hyaluronic acid . Wrinkles appear when this part of the skin deteriorates. Taking care of your dermis has kept your skin young and healthy.

The hypodermis

The third layer, the hypodermis, is made up mostly of fat cells and collagen fibers, with mostly blood vessels. It stores energy, while insulating our body. It is therefore a thermal protection and a source of energy.

The hydrolipidic film

The skin is covered by an emulsion of water and fat, which forms the hydrolipidic film. The sebaceous gland produces sebum, then pushes it out through the pores. The sweat gland generates some sweat and also pushes it out through the pores. Sebum and sweat meet on the surface of the skin, mix and create a hydrolipidic layer. It is an impermeable layer, which first prevents water from entering, and on the other hand, retains water from leaving the body. It also helps the skin to be supple. But the most important thing is that it is a real protective barrier against bacteria and fungi.

In summary

From a chemical point of view, the skin comprises on average 70% water, 27.5% protein, 2% fat and 0.5% mineral salts and trace elements. It performs various vital functions such as protection, perception, sensitivity and maintaining a balanced metabolism. The skin renews itself every 3-4 weeks.

The epidermis, the dermis and the hypodermis, these different layers of the skin, differ according to the parts of the body, as well as between women and men. They also change with age. To take care of your skin, you must also take into account your lifestyle, the environment and the climate. This is why it is important to understand them in order to take care of them.