The Skin

Covering an area of about two square meters, the skin is the largest and functionally most versatile organ of the human organism. The skin cells not only protect the organism against pathogens and exposure to sunlight, but also from overheating and dehydration. The skin also has many other jobs: the nerve cells that are embedded in the skin enable man to detect temperature and discover the world through touch. In addition, oxygen and substances can be absorbed through the skin. Likewise, harmful substances can be excreted through the skin. The skin consists of three functional layers: the epidermis, the dermis and subcutis.

The epidermis is the outer covering of the body. In some places it is only 0.1 mm thick. A water-fat emulsion produced by the sebaceous glands and sweat glands helps the skin maintain its suppleness. The acidity of this emulsion also protects the skin against external influences such as bacteria. The epidermis wears out quickly and is constantly renewing itself. It completely rebuilds with a period of about four weeks.

Lying beneath the epidermis is the much stronger dermis. A network of collagen fibers ensures its high elasticity and pulls the dermis in all directions. Also found in the dermis are the sweat, scent and sebaceous glands as well as the tiniest blood vessels which supply the skin with nutrients. The dermis is responsible for the outer appearance of the skin.

The subcutaneous tissue or subcutis is the fatty tissue found under the skin. It acts as a water and energy reservoir and protects the skin from hypothermia and shock. The fat cells are embedded in a loose network of connective tissue and held by collagen fibers. One-third of the fluid in the human organism is located in the subcutis.