What protective feature is primarily responsible for preventing water loss from the skin?

The stratum corneum is the outermost layer of the skin and plays a crucial role in protecting the body from water loss. It is composed of dead skin cells that act as a barrier, preventing transepidermal water loss (TEWL) by retaining moisture within the deeper layers of the skin. This layer is essential for maintaining skin hydration and integrity, as well as preventing external contaminants from penetrating the skin.

The stratum basal layer, while important for generating new skin cells, does not serve the primary function of preventing water loss. Hair follicles contribute to skin health but are not directly involved in preventing moisture loss. Sebum production is beneficial for lubricating and protecting the skin, but it is the stratum corneum that is the primary defense against dehydration. Thus, the stratum corneum is fundamentally responsible for maintaining skin hydration.