What is the function of the stratum corneum?

The stratum corneum, which is the outermost layer of the skin, serves a vital role in protecting the body. Its primary function is to provide a barrier against environmental damage, which includes protection from pathogens, chemicals, and physical abrasions. The cells in the stratum corneum are keratinized and often referred to as corneocytes. These dead cells are tightly packed and filled with keratin, a tough protein that contributes to the skin's resilience and water resistance.

This barrier function is critical for maintaining hydration levels in the skin, as it prevents excessive water loss and helps to keep the skin hydrated. Moreover, the stratum corneum acts as a shield against UV radiation and environmental pollutants, contributing to overall skin health and integrity.

In contrast, the other options pertain to functions that occur in different layers or systems of the skin. Melanin production takes place in the melanocytes located in the deeper layers of the epidermis, fat storage occurs primarily in the subcutaneous tissue (hypodermis), and blood circulation is governed by blood vessels in the dermis rather than the outer layer of skin. Understanding these distinctions helps to clarify the unique and essential role of the stratum corneum in skin function