What is the outer layer of the skin called?

The outer layer of the skin is known as the epidermis. This layer serves as the body's first line of defense against environmental factors such as pathogens, chemical exposure, and physical injuries. It is composed primarily of keratinized stratified squamous epithelium, which provides both protection and structure. The epidermis is also responsible for the production of melanin, which contributes to skin pigmentation and protection from ultraviolet radiation.

In addition, the epidermis varies in thickness depending on the area of the body, being thinnest on areas like the eyelids and thickest on the palms of the hands and soles of the feet, reflecting its functional importance. Its structure includes several distinct layers, such as the stratum corneum and stratum basale, contributing to its role in skin regeneration and barrier function.