The skin is made up of three layers: the epidermis, dermis and fat layer, also known as the subcutaneous layer. All layers combined protect the body's muscles, nerves, internal organs and blood vessels. Each layer of skin performs a specific task. The epidermis specifically prevents bacteria and viruses from entering the body, the dermis gives the skin its strength and flexibility and the fat layer insulates the body from hot and cold. Most skin cells are found in the epidermis. The epidermis is a thin, tough, outer layer of the skin made up of the outermost portion known as the stratum corneum, and the deepest layer known as the basal layer. The skin cells in the epidermis are keratinocytes, melanocytes and Langerhans cells.
Keratinocytes
Skin cells that make up the epidermis are named keratinocytes. Keratinocytes originate from the innermost layer of the epidermis, the basal layer, and slowly migrate toward the surface of the epidermis. Once the keratinocytes reach the surface of the skin they gradually shed and are replaced by younger keratinocytes. These skin cells provide a layer of protection between you and the environment. They prevent toxic substances in the environment from entering your body.
Melanocytes
The basal layer of the skin contains cells known as melanocytes. Melanocyte cells contain intracytoplasmic organelle, the melanosome in which the pigment melanin is produced and deposited. Melanocyte cell activity is the major determinant of the color of your skin and hair. The melanin produced from the melanocytes cells also acts to filter out ultraviolet radiation from sunlight, preventing damage to the skin and risk of skin cancer.
Langerhans Cells
The epidermis also contains Langerhans cells, which are vital to the skin's immune system. These skin cells help defend the body against infection, detect foreign substance in the body and play a role in the development of skin allergies.
Fat Cells
The fat layer of the skin lies below the dermis and acts to insulate the body from heat and cold, provides protective padding and stores energy in the body. The fat is contained in living fat cells, which are held together by fibrous tissues.
