The epidermis is primarily composed of what?

The epidermis, which is the outermost layer of the skin, is primarily composed of keratinocytes. These cells are responsible for forming a protective barrier and are crucial in the process of keratinization, where they produce keratin, a protein that helps strengthen the skin. Keratinocytes make up about 90% of the cells in the epidermis and undergo a cycle of growth, differentiation, and eventual shedding as they move from the basal layer of the epidermis to the surface.

In contrast, melanocytes, although present in the epidermis, are responsible for producing the pigment melanin and make up a smaller percentage of the cellular composition. Fibroblasts are found in the dermis, below the epidermis, and play a significant role in collagen production and skin elasticity. Adipocytes, or fat cells, are primarily located in the subcutaneous layer beneath the dermis and are involved in storing energy and insulating the body. Thus, while all these cells play important roles in skin health, keratinocytes are the predominant cells in the epidermis.