Melanocytes have long, dendritic processes that reach the upper and lower layers of the epidermis. Through these dendrites melanocytes transfer melanosom to the keratinocytes. Melanosomes are melanin-containing organelles that are synthesized by the melanocytes. Dark skin individuals produce more melanosomes and transfer more melanosomes to the keratinocytes. However interestingly, in different races the number of melanocytes is constant for a given cutaneous site.
Melanocytes are the cells which give rise to the development of malignant melanoma.
The function of melanin is to provide protection against the damaging effects of ultraviolet light. Individuals with light complexion and less melanin are prone to develop premature skin aging, precancerous skin lesions, and skin cancers of various types as a result of cumulative sun exposure. They participate in the development of contact hypersensitivity. Merkel Cells are found in, or near, the basal cell layer of the epidermis. They surround hair follicles and are speculated to assist the touch receptors.