What is the primary type of cell found in the epidermis?

The primary type of cell found in the epidermis is keratinocytes. These cells make up about 90% of the epidermal layer and are crucial for the skin's protective functions. Keratinocytes originate from the basal layer of the epidermis, where they continuously divide and migrate upwards towards the surface. As they move, they undergo a process known as keratinization, where they become filled with the protein keratin, ultimately leading to the formation of a tough and protective outer layer of skin. This layer serves as a barrier to pathogens, prevent water loss, and protect underlying tissues from environmental damage.

In contrast, adipocytes are fat cells primarily found in the subcutaneous layer, beneath the skin, and are not involved in the function of the epidermis. Fibroblasts are connective tissue cells found in the dermis, responsible for producing collagen and extracellular matrix, which provide structural support to the skin. Melanocytes, while important for pigmentation and protecting against UV radiation, constitute a smaller percentage of cells within the epidermis compared to keratinocytes. Thus, the dominance of keratinocytes in the epidermis is vital for the overall health and functionality of the skin.