What is the deepest layer of the epidermis that contains stem cells?

The deepest layer of the epidermis that contains stem cells is the stratum basale. This layer serves as the foundation of the epidermis and is crucial for the generation of new skin cells. It is composed primarily of a single row of columnar or cuboidal basal cells that are actively dividing. These stem cells continuously undergo mitosis, producing new keratinocytes that migrate up through the layers of the epidermis, ultimately replacing the cells that are shed from the surface.

The stratum basale is also important because it contains melanocytes, which produce melanin, and Merkel cells, which are involved in sensory perception. The presence of stem cells in this layer is essential for the skin's ability to repair and regenerate itself, making it a key player in maintaining skin integrity.

In contrast, the other layers mentioned do not contain stem cells. The stratum corneum is the outermost layer composed mainly of dead keratinized cells. The stratum spinosum contains several layers of keratinocytes that have lost their ability to divide but are still involved in strengthening the skin. The stratum granulosum is where keratinocytes begin to undergo a process of keratinization, losing their nuclei and becoming more flattened, which further distances