Glossary

Skin is made up of the epidermis, the dermis and the hypodermis (subcutaneous tissue). But in everyday language, what we call skin is in fact the most exterior part of the skin, the visible layer, essentially made up of keratocytes. This part, 0.1 to 0.2 millimetres' thick, is known as the epidermis. Keratocytes include germ cells of mature cells located under the corneocytes, nucleus-free cells, filled with a hard matter called keratin and that form our skin's stratum corneum. During their migration to the surface, keratocytes produce corneocytes that form the stratum corneum. Under the epidermis can be found the dermis, the thickest part of the skin. It houses the blood vessels that feed the skin, the nerves that make it sensitive and the collagen and elastin fibres that give it its suppleness. There are also hair follicles, sebaceous glands that secrete the sebum and grease the skin's surface, sweat glands that secrete sweat, thus eliminating toxins, as well as an entanglement of little blood vessels and fibres. Even deeper can be found the hypodermis (subcutaneous tissue), a fatty layer than protects the body from attacks and external pressure and that forms a layer on which the superficial part of the skin can slide over.