More than just a shell, the skin is an organ in its own right. It is even one whose weight and size are most important. Real interfaces with the outside world, it protects other organs from infections, injuries and harmful solar rays. Blessed with extreme sensitivity, it allows the sense of touch.
The skin consists of three superimposed compartments: the epidermis, dermis and hypodermis.
The epidermis
The skin is composed of two tissues: an outer layer called epidermis and an inner layer called the dermis or corium. The surface of the skin, the epidermis, is composed of dead cells that are removed when the subject moves, when he puts on clothes or when washing. This layer of dead cells is often called the “fake skin”. The epidermis has four layers: the basal layer of Malpighi, the granular layer and stratum corneum.
The dermis
Just below the epidermis lies the dermis, where every second cells proliferate to replace those removed.
The dermis (or corium) is thicker tissue, relatively flexible, which is the innermost layer of the skin. It enables the protection and repair of damaged tissues and is four times thicker than the epidermis (outer layer of skin). The dermis is composed primarily of protein called collagen, which develops scar tissue to repair cuts and abrasions. The dermis nourishes the epidermis and contains nerve endings and blood vessels, and sometimes fat. The base of the hair is also located in the dermis. Beneath the dermis lies the hypodermis, a layer of fat under the skin.
The hypodermis
Located in the dermis, the subcutaneous tissue is rich in fat and blood vessels. Its main role is to absorb the pressures to which the skin is subjected. It also protects the body temperature variations. It is particularly important in areas to withstand an impact such as the buttocks or heels. However in other areas, it is virtually nonexistent.