What is the primary function of the epidermis?

The primary function of the epidermis is to act as a protective barrier for the body. This outermost layer of skin serves several purposes related to protection, including providing a shield against environmental hazards such as pathogens (bacteria, viruses, and fungi), chemicals, and physical abrasions. The epidermis contains keratinocytes, which produce keratin, a tough protein that helps make the skin resilient and water-resistant. Additionally, the epidermis is involved in preventing water loss from the body, which contributes to overall hydration and homeostasis.

While temperature regulation is an important function of the skin as a whole, it is largely managed by the dermis, which contains blood vessels and sweat glands. Fat storage is primarily a function of the subcutaneous layer beneath the skin, not the epidermis. Blood cell production occurs in the bone marrow, not in the skin layers.