Where are Langerhans cells primarily located in the skin?

Langerhans cells are primarily located in the stratum spinosum layer of the epidermis. This layer is situated just above the stratum granulosum and is characterized by a spiny appearance due to desmosomal connections between keratinocytes. Langerhans cells function as antigen-presenting cells that play a key role in the immune response of the skin. They help detect and capture pathogens, and then migrate to the lymph nodes to activate T-cells, thereby facilitating the body's immune response.

Their presence in the stratum spinosum allows them to effectively monitor for foreign invaders as they are strategically positioned between the keratinocytes, which are the predominant cell type in this layer. Understanding the location and role of Langerhans cells is crucial for estheticians, especially when considering treatments that may affect the skin's immune functions.