Canadian Health Information Management Association Practice Exam

Which epidermal cell is primarily responsible for immunity and disease resistance?

1. Keratinocytes

2. Langerhans cells

3. Melanocytes

4. Merkel cells

The correct answer is: Langerhans cells

Langerhans cells are specialized dendritic cells located in the epidermis that play a crucial role in the skin's immune response. They are responsible for recognizing foreign pathogens, such as bacteria and viruses, and presenting that information to T cells, a type of white blood cell that is central to the immune system. This interaction is vital for initiating an immune response, making Langerhans cells essential for maintaining disease resistance. In contrast, other types of epidermal cells serve different functions. Keratinocytes are the predominant cells in the epidermis and primarily focus on forming the protective barrier of the skin by producing keratin. Melanocytes are involved in the production of melanin, which gives skin its color and protects against UV radiation but is not directly involved in immune responses. Merkel cells are sensory cells that contribute to the sensation of touch, and while they are important for sensory perception, they do not play a direct role in immunity. Thus, Langerhans cells distinctly stand out as the key epidermal cell in understanding immunity and disease resistance in the skin.