(1) The innermost layer of the epidermis made up of basal or germinative cells capable of proliferating by mitosis to give rise to new cells for other epidermal layers.
(2) The layer of endometrium that is less responsive to hormonal stimuli and does not desquamate, but preserved. It gives rise to the new functional layer shed during a menstrual period.
In the skin, the cells of basal layer are actively dividing to replenish lost skin cells from normal shedding. This layer has many melanocytes, or melanin-producing cells that account for the pigmentation of skin and hair.
In the endometrium, the basal layer is a layer of cells that is located underneath the functional layer. Unlike the functional layer, the basal layer is not shed during menstruation.
Synonym: stratum basale.