What is the main function of the stratum lucidum?

The stratum lucidum primarily functions to protect areas of thick skin, which is found mainly on the palms of the hands and the soles of the feet. This thin, transparent layer of cells provides an extra level of protection and contributes to the overall durability of the skin in high-friction areas.

This layer is composed of dead keratinocytes that contain a protein called eleidin, which helps to provide a barrier that strengthens the skin. The presence of the stratum lucidum is crucial for maintaining the integrity and function of the epidermis in areas subjected to continuous stress and abrasion.

While the other options mention important skin functions, they do not accurately describe the specific role of the stratum lucidum. For example, immune protection is mainly provided by the immune cells found in the deeper layers of the skin, and the barrier against water loss is primarily the function of the stratum corneum. Cell division occurs in the stratum basale, the deepest layer of the epidermis, where new cells are generated.