What are corneocytes?

Corneocytes are indeed hardened keratinocytes, which are the primary cells found in the outermost layer of the skin, known as the stratum corneum. These cells play a crucial role in the skin's barrier function. As keratinocytes move up from the deeper layers of the epidermis to the surface, they undergo a process called keratinization, where they become filled with keratin, a tough and protective protein. During this process, they lose their nuclei and cell structure, effectively transforming them into corneocytes.

The significance of corneocytes lies in their contribution to the skin's natural barrier, which protects against environmental aggressors, prevents transepidermal water loss, and helps maintain hydration. By forming a tough, protective layer, corneocytes help skin stay resilient, healthy, and able to withstand external stresses.

In contrast, the other options do not accurately describe the role or nature of corneocytes. Living skin cells would refer to cells that are still metabolically active, while corneocytes are no longer living. Fatty tissues beneath the skin pertain to subcutaneous tissue, and cells responsible for skin color refer to melanocytes, which produce melanin. Therefore, the characterization of corneocytes