Which layer of skin is primarily composed of dead cells?

The stratum corneum is the outermost layer of the epidermis and is primarily composed of dead, flat keratinized cells. This layer serves as a protective barrier, preventing water loss from the body and shielding the underlying layers from environmental damage, pathogens, and chemical exposure. The cells in the stratum corneum are rich in keratin, a tough protein that adds to the layer's durability and makes it an effective barrier.

In contrast, the other layers of the epidermis, such as the stratum granulosum, stratum lucidum, and stratum basale, consist of living cells that are actively involved in processes such as producing new skin cells (in the stratum basale) or transitioning in structure and function as they move toward the surface. These layers contribute to the overall function of the skin but do not primarily consist of dead cells like the stratum corneum.