Which layer of the skin is referred to as the epidermis?

The epidermis is known as the outer layer of the skin. It serves as the body's first line of defense against environmental factors, such as bacteria, UV radiation, and dehydration. The epidermis is also responsible for the production of new skin cells, as it contains keratinocytes, which play a critical role in forming the protective barrier of the skin. Additionally, this layer is where pigmentation occurs, involving cells called melanocytes that produce melanin, the pigment responsible for skin color.

The other layers of skin—such as the inner layer (dermis), the middle layer (subcutaneous layer), and the fatty layer—play different roles that support the functions of the epidermis. The dermis is situated beneath the epidermis and is much thicker, containing blood vessels, connective tissue, hair follicles, and other structures that support and nourish the epidermis. Meanwhile, the subcutaneous layer consists mainly of fatty tissue, providing insulation and cushioning for the body. Understanding these layers is crucial in the study of skin anatomy as it relates to cosmetology practices.