Which layer of the epidermis comprises fully keratinised cells?

The stratum corneum is the outermost layer of the epidermis and is composed of fully keratinized cells. These cells, known as corneocytes, are flattened and filled with keratin, a tough protein that provides the skin with its protective properties. The primary function of the stratum corneum is to act as a barrier against environmental damage, pathogens, and dehydration.

As the skin matures, cells in the lower layers undergo a process known as keratinization, where they progressively move upward, becoming more keratinized until they reach the stratum corneum, where they eventually shed off in a process called desquamation. This layer is essential for maintaining skin health and preventing water loss.

Understanding this structure is key for professionals in skin health, as it informs practices related to skincare products, treatments, and overall skin protection strategies. The other layers mentioned have different characteristics and functions, with none reaching the level of keratinization found in the stratum corneum.