Which type of skin cell is responsible for sensing light touch?

• A. Langerhans cells
• B. Merkel cells
• C. Keratinocytes
• D. Melanocytes

Answer: (B)

Merkel cells are specialized skin cells located in the epidermis, particularly within the stratum basale. Their primary function is to serve as mechanoreceptors, which means they are responsible for sensing light touch. These cells are connected to sensory nerve endings and help in the detection of texture and shapes, contributing to the sense of touch. When the skin is lightly tapped or brushed, Merkel cells detect this stimulation and relay information to the nervous system, allowing for the perception of touch sensations.

In contrast, Langerhans cells are primarily involved in immune response, acting as antigen-presenting cells that help defend against pathogens. Keratinocytes are the predominant cell type in the epidermis that produce keratin, a key structural protein for skin protection and barrier function. Melanocytes are responsible for producing melanin, the pigment that gives skin its color and protects against UV radiation. Each of these cell types plays a distinct role in skin physiology, but only Merkel cells are specifically specialized for the function of sensing light touch.