What cell is responsible for skin pigmentation?
A. Langerhans
B. Keratinocyte
c. Melanocyte
The correct answer and explanation is:
The correct answer is C. Melanocyte.
Melanocytes are the cells responsible for producing melanin, the pigment responsible for the color of the skin, hair, and eyes. These cells are located primarily in the epidermis, the outermost layer of the skin. Specifically, they are concentrated in the stratum basale, the deepest layer of the epidermis.
Melanin is produced in response to ultraviolet (UV) light exposure. When the skin is exposed to UV radiation, melanocytes increase the production of melanin as a protective response. The melanin absorbs and dissipates UV radiation, helping to prevent DNA damage that could lead to skin cancer. This process is known as melanogenesis. Melanin is then transferred from melanocytes to the surrounding keratinocytes, the most abundant cell type in the epidermis. These keratinocytes carry the pigment upward, where it accumulates to form a protective layer in the skin.
There are different types of melanin: eumelanin, which is brown or black, and pheomelanin, which is yellow or red. The ratio and type of melanin produced by melanocytes contribute to the wide range of human skin colors.
Langerhans cells (A) are part of the immune system and play a role in detecting foreign invaders. Keratinocytes (B) are responsible for forming the protective barrier of the skin and for producing keratin, which strengthens the skin. Merkel cells (D) are involved in sensation, particularly in detecting touch and pressure. While all these cells have essential functions in the skin, only melanocytes are involved in pigmentation.