Question

Melanin pigment of human skin is produced by-
A. Mast cells of corium
B. Melanocytes of corium and incorporated there
C. Melanocytes of corium and incorporated in epidermis
D. Melanocytes of epidermis

Answer 1

Hint: The cells originating from the neural crest are found in the lower layer or the inner lining of the organs and contribute to long-lasting pigmentation. They play a part in the immune system as well.

Complete answer:
Option A is incorrect. A mast cell is a migrant cell of connective tissue that produces several granules rich in histamine and heparin (also known as a mastocyte or a labrocyte). Specifically, it is a type of myeloid stem cell-derived granulocyte that is part of the immune and neuroimmune systems.
Option B is incorrect. Melanocytes in the epidermis and hair follicles are found in the human skin. The potential for the development of melanin and the origin of neural crest cells are the fundamental characteristics of these cells. Melanocytes manufacture melanin, which is a pigment found in the skin, eyes, hair, nasal cavity, and inner ear, in a process called melanogenesis.
Option C is correct. Melanin is a pigment in melanocytes or skin cells formed within the skin when they are exposed to the sun. The mechanism through which the melanocytes form the pigment melanin is referred to as melanogenesis. Within a tiny membrane-bound structure called melanosomes, the pigment is produced. A skin colour under the dermis or corium produced by connective tissue which is bluish-white colour and by the haemoglobin circulating in the corium veins. Corium is a skin layer which is situated between the epidermis and the subcutaneous tissues of the skin. Two types of melanin are produced in the body, pheomelanin (red to yellow in colour) and eumelanin (dark brown to black). The ones with light complexions produce pheomelanin, and the one with dark complexions produce eumelanin.
Option D is incorrect. Melanocytes in the epidermis and hair follicles are found in the human skin. The potential for the development of melanin and the origin of neural crest cells are the fundamental characteristics of these cells. UVA radiation causes melanocytes, which are the skin cells that produce the skin pigment known as melanin, to suffer lesions or DNA damage. Melanin is a protective skin pigment that blocks UV radiation from harmful DNA and is potentially responsible for skin cancer.

So, the correct answer is Option C.

Note: Melanocytes are also part of the immune system, and are known to be immune cells, in addition to their function as UV radical scavengers. Melanocytes are capable of recognizing Class II MHC, expressed only by certain immune system antigen presenting cells, when activated by antigen or cytokine interactions.