Which cells are involved in initiating immune responses in the skin?

a. Langerhans cells
b. Merkel cells
c. Keratinocytes
d. Melanocyte

ANS: A
The Langerhans cells process the antigen and carry it to T cells. T cells then become sensitized to the antigen, inducing the release of inflammatory cytokines and the symptoms of dermatitis. Merkel cells are associated with nerve cells. Keratinocytes are part of the epidermal layer of the skin and are not involved in immune responses. Melanocytes synthesize the skin's pigment.