# Melanocyte --- A **melanocyte** is a type of [[cell]] found in the [[epidermis]] and [[hair#The Hair Follicle Bulb|hair bulbs]] that produces the [[pigment]] **melanin**. Melanin works to protect the skin cells from damaging [[radiation|UV radiation]], and also darkens the color or the skin. The base of the cell lives in the [[epidermis#Stratum Basale|stratum basale]], but it has many tendrils that stretch out into the [[epidermis#Stratum Spinosum|stratum spinosum]] to spread out the **melanosomes**. A build-up of melanocytes is a *mole*. ![[melanocyte.png]] ## Melanin & Melanosomes **Melanin** has a few different forms, and can be black, brown, tan and yellow-brown. Melanin comes in two main types, **eumelanin** (which is blackish and brownish) and **pheomelanin** (which is reddish). When melanin builds up in the nucleus of [[epidermis|keratinocytes]] we can see it as darker skin color. When exposed to [[radiation|UV radiation]], keratinocytes send a signal to melanocytes to produce more melanin. After exposure it takes about 10 days after exposure to for peak melanin production. A build up of melanin can protect the skin from radiation, but it can also hinder the production of [[vitamin D]]. **Melanosomes** are [[vesicle|vesicles]] filled with melanin that travel from melanosomes to the surrounding keratinocytes where they then burst open, depositing the melanin payload. When those keratinocytes slough off after UV-exposure melanin-overproduction we see can see it as "loosing a tan". ___