epidermis

The epidermis is the outermost layer of skin that serves as a protective barrier for the body. It is composed of several layers of cells, primarily keratinocytes, which produce keratin, a protein that helps make the skin tough and waterproof. The epidermis also contains melanocytes, which produce melanin, responsible for skin color and protection against UV radiation. Unlike deeper skin layers, the epidermis does not contain blood vessels; instead, it relies on the underlying layers for nutrients. Its primary functions include safeguarding against environmental damage, preventing water loss, and helping with sensation.