What is the outer layer of the epidermis known as?

The outer layer of the epidermis is known as the stratum corneum. This layer is composed of dead, flattened skin cells that are filled with keratin, a protein that helps protect the skin from external elements such as bacteria, chemicals, and physical abrasions. The stratum corneum serves as the first line of defense against environmental damage and plays a vital role in preventing water loss from the body, contributing to overall skin hydration and health.

The other layers mentioned, such as the stratum lucidum, stratum granulosum, and stratum basale, are located beneath the stratum corneum and have different functions in the skin's structure and health. For example, the stratum lucidum is a thin layer found only in certain areas of thick skin, the stratum granulosum contains cells that are beginning to lose their nuclei and become keratinized, and the stratum basale is the deepest layer where new skin cells are generated. Understanding the roles of these different layers helps in comprehending how skin protection and regeneration function.