In the epidermis there are mainly three types of cells: keratinocytes, melanocytes and Langerhans cells. New keratinocytes are formed in the lowermost layer of the epidermis. From there they migrate upwards towards the skin’s surface, changing shape as they go, dying slowly, until they arrive at the surface of the skin to form a protective layer. The cornified skin cells are closely packed and embedded in protective layers.

Melanocytes form pigments, thereby protecting the skin against the negative influence of sunlight. Langerhans cells are the defence cells of the immune system in the skin. They are able to recognize invasive foreign bodies and send alarms to the body’s immune system.

The connective cells in the dermis, called fibroblasts, provide material to build a three-dimensional framework of fibrous proteins (collagen, Elastin) and other macro-molecules which, as an extra-cellular matrix, keep the skin stable and flexible.

Skin receptors act like antennas and are responsible for the perception of sensory irritation which is then forwarded to the nervous system. As sensory organ “par excellence”, the skin contains 200 pain receptors, 100 pressure receptors, 12 cold receptors and 2 warmth receptors per square centimetre. In addition, 100 sweat glands and 40 sebaceous glands are embedded in every square centimetre of the skin. The numbers depend on the site of the body.