The innermost layer, usually made up of a single layer of tall, simple columnar epithelial cells that lies at the base of the epidermis or above the dermis.
The layer is made up of a single layer of basal cells. The cells of this layer are actively dividing to provide new cells to replenish lost skin from normal shedding. In hyperproliferative epidermis, this layer may be composed of two to three cells thick.
This layer has many melanocytes, or melanin-producing cells that account for the pigmentation of skin and hair.
Synonyms: stratum basale epidermidis, stratum cylindricum, stratum germinativum.
Compare: stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum.
See also: epidermis, Malpighian layer.