Which layer of the epidermis is known as the horny layer?

The layer of the epidermis known as the horny layer is the stratum corneum. This outermost layer plays a crucial role in skin health and function. Composed of dead keratinized cells, the stratum corneum provides a strong barrier against environmental factors such as pathogens and moisture loss. Its thickness can vary depending on the area of the body, contributing to the skin's overall resilience and protective capabilities.

Understanding the stratum corneum's function is essential for estheticians, as it impacts everything from skin hydration to the effectiveness of skincare products. Proper exfoliation techniques often target this layer to promote better skin cell turnover and enhance the absorption of active ingredients from topical treatments.

The other layers of the epidermis, while important, serve different functions. For example, the stratum lucidum acts as a barrier for areas of thick skin, the stratum granulosum is where keratinization begins, and the stratum basale is primarily involved in the generation of new skin cells. Each layer contributes to the health and appearance of the skin, but it's the stratum corneum that is specifically recognized as the horny layer due to its composition and protective qualities.