What is the term for the outermost layer of the skin?

The outermost 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 bacteria, UV radiation, and moisture loss. The epidermis is primarily composed of keratinized epithelial cells, providing a protective barrier. Within the epidermis, there are several sub-layers, including the stratum corneum, which consists of dead, flattened skin cells that help to prevent water loss and keep the underlying layers hydrated.

The dermis, which is another layer of skin, lies beneath the epidermis and contains connective tissue, blood vessels, and nerve endings, contributing to the skin's structural integrity and sensory functions. The hypodermis, also known as the subcutaneous layer, is located below the dermis and is mainly composed of fat and connective tissue, playing a role in insulation and cushioning the skin. Although the stratum corneum is a vital part of the epidermis, it is not the term used to describe the entire outermost layer of skin. Therefore, the correct term for the outermost layer of the skin is indeed the epidermis.