Laser Technician (International Board of Electrologist Certification) IBEC Board Exam

Which cellular structure is primarily involved in touch sensation at the skin surface?

1. Keratinocytes

2. Merkel cells

3. Fibroblasts

4. Langerhans cells

The correct answer is: Merkel cells

The correct answer is that Merkel cells play a key role in the sensation of touch at the skin's surface. These specialized cells are located in the basal layer of the epidermis and are closely associated with sensory nerve endings, forming what are known as Merkel cell-neurite complexes. This unique relationship allows Merkel cells to function as mechanoreceptors, which means they respond to mechanical pressure or distortion. Upon activation by touch, they transmit signals to the nervous system, contributing to the perception of fine touch, texture, and shape. Keratinocytes, while they make up the majority of the epidermis and provide protective functions, are not directly involved in sensory perception. Fibroblasts, on the other hand, are primarily involved in the production of collagen and extracellular matrix in the dermal layer but do not have a role in touch sensation. Langerhans cells are part of the immune response in the skin and help in identifying pathogens but do not function in touch sensitivity. Hence, the distinct role of Merkel cells in touch sensation solidifies their importance in this context.