basal layer

The basal layer, or stratum basale, is the innermost layer of the epidermis, the protective outer portion of the skin. It is a living layer where new skin cells, called keratinocytes, are continuously formed through mitosis. These cells then migrate outward, undergoing changes as they move toward the skin's surface. The epidermis itself is divided into two main parts: the living basal layer and the superficial stratum corneum, which is composed of dead, keratin-filled cells. The basal layer is crucial for skin renewal and contains melanocytes, which are responsible for skin color. This layer depends on diffusion from the dermis for its metabolic needs, as it lacks its own blood supply.1234