By the time the cells reach the outermost layer- called stratum corneum- all that’s left of the dead cells is their keratin. The newly arriving flattened cells called keratinocytes, they replace the dead cells that flake away with daily wear
As the cells are pushed upward, they stop dividing and instead produce keratin, a tough, fibrous protein. The keratin replaces the cytoplasm and nucleus in each cell. The cells flatten, and as they move further away from their blood supply, they die
The stratum basale, or basal layer, also called the stratum germinativum- is the innermost layer. It consists of a layer of columnar stem cells. These stem cells continually undergo mitosis, producing new skin cells. As new cells are produced, they push the older cells upward, toward the skin’s surface