|Melanocyte and melanin.|
Melanocytes are melanin-producing cells. They are most obvious in the skin, hair and eyes. They are in the bottom layer of the skin's epidermis, in hairs, and in the iris of the eye, and some places inside the body.
Melanin is the pigment mostly responsible for skin and hair colour. It protects the skin against damage by UV radiation from the Sun. UV radiation causes damage to cell DNA, which makes skin cancer more likely.
Melanocyte-stimulating hormones (MSH) from the pituitary gland causes melanocytes to produce more melanin. They stimulate the production and release of melanin by melanocytes in skin and hair. MSH signals to the brain have effects on appetite and sexual arousal.