Which layer of the epidermis provides protection against UV radiation?

The layer of the epidermis that provides protection against UV radiation is the Stratum Basale. This deepest layer is crucial for producing new skin cells, specifically keratinocytes, which migrate upwards through the layers of the epidermis. While the Stratum Basale itself does not directly absorb UV radiation, it is responsible for the production of melanin, a pigment that is essential for protecting the skin from damaging effects of ultraviolet light. Melanin absorbs and dissipates UV radiation, thereby reducing the risk of DNA damage that can lead to skin cancer.

In contrast, the Stratum Corneum serves primarily as a barrier to water loss and external pollutants, while the Stratum Lucidum is typically found only in thick skin areas like palms and soles, offering minimal UV protection. The Stratum Spinosum plays a role in the immune response and skin strength but is not directly involved in UV protection. Thus, the Stratum Basale's function in melanin production is key to its role in shielding the skin from harmful UV rays.