What is the primary function of the epidermis?

The primary function of the epidermis is to serve as a protective barrier against environmental hazards. The epidermis is the outermost layer of the skin and plays a critical role in safeguarding the internal structures of the body from potential threats such as pathogens, UV radiation, and chemical exposure. Its keratinized cells provide a tough, impermeable layer that helps prevent water loss, while also serving as a frontline defense against infections and environmental damage. This barrier function is essential for maintaining overall skin health and protecting the body from external harm.

While the support of blood vessels and nerves is important for skin physiology, this function is primarily associated with deeper layers of the skin, such as the dermis. Storing energy in the form of fat is a function of the subcutaneous layer, not the epidermis. Additionally, the production of sweat and oil is carried out by glands located in the dermis, further emphasizing that the main role of the epidermis is to act as a protective barrier.