In which layer of the skin does mitosis occur?

Mitosis, the process of cell division that leads to the formation of new cells, primarily takes place in the stratum germinativum, also known as the basal layer of the epidermis. This layer is located just above the dermis and consists of a single row of columnar or cuboidal cells that are actively dividing. As these cells undergo mitosis, they push older cells towards the surface of the skin, leading to the continual renewal of the epidermis.

The stratum germinativum is crucial for maintaining the overall health and integrity of the skin because it provides the cells needed to replace those that are shed from the upper layers. The other layers, such as the stratum corneum, stratum granulosum, and stratum spinosum, primarily consist of cells that are in different stages of development and maturation, with the stratum corneum being made up of dead, flattened cells that have lost their nuclei and are no longer capable of division.