What type of cells are primarily found in the stratum corneum?

The stratum corneum is the outermost layer of the epidermis, primarily composed of keratinocytes. These cells are specialized for the production of keratin, a protein that provides a barrier to protect the underlying layers of the skin from environmental threats such as pathogens, chemical irritants, and dehydration. In the stratum corneum, keratinocytes are in a state of terminal differentiation, meaning they lose their nuclei and organelles, becoming flattened and densely packed with keratin.

This layer acts as the body’s primary defense against external factors, and its composition of keratinocytes is vital for maintaining skin hydration and overall integrity. Other cells, like melanocytes (which produce melanin), fibroblasts (which are found in the dermis and contribute to collagen production), and adipocytes (fat cells found primarily in the subcutaneous layer), do not primarily inhabit the stratum corneum, which underscores the importance of keratinocytes in this specific layer of the skin.