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Melanocytes are melanin-producing neural crest-derived [3] cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), [4] the inner ear, [5] vaginal epithelium, [6] meninges, [7] bones, [8] and heart found in many mammals and birds. [9] Melanin is a dark pigment primarily responsible ...
The skin of face and hands has about twice the amount of pigment cells as unexposed areas of the body, as chronic exposure to the sun continues to stimulate melanocytes. The blotchy appearance of skin color in the face and hands of older people is due to the uneven distribution of pigment cells and to changes in the interaction between ...
A melanocytic nevus (also known as nevocytic nevus, nevus-cell nevus, and commonly as a mole) [1] [2] is usually a noncancerous condition of pigment-producing skin cells. It is a type of melanocytic tumor that contains nevus cells. [2]
Biological pigments include plant pigments and flower pigments. Many biological structures, such as skin, eyes, feathers, fur and hair contain pigments such as melanin in specialized cells called chromatophores. In some species, pigments accrue over very long periods during an individual's lifespan. [2]
Melanin pigments are produced in a specialized group of cells known as melanocytes. There are five basic types of melanin: eumelanin, pheomelanin, neuromelanin, allomelanin and pyomelanin. [2] Melanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino acid tyrosine is followed by ...
Skin pigmentation in humans evolved to primarily regulate the amount of ultraviolet radiation (UVR) penetrating the skin, controlling its biochemical effects. [17] The actual skin colour of different humans is affected by many substances, although the single most important substance determining human skin colour is the pigment melanin.
A study links graying hair to stem cells getting stuck, unable to color new hair growth. And here's the good news: That might mean gray hair is reversible. A Study Says Gray Hair May Be Reversible
Chromatophores in the skin of a squid. Chromatophores are cells that produce color, of which many types are pigment-containing cells, or groups of cells, found in a wide range of animals including amphibians, fish, reptiles, crustaceans and cephalopods. Mammals and birds, in contrast, have a class of cells called melanocytes for coloration.