Which layer of the epidermis consists of flattened, dead cells that are hardened?

The epidermis is the outermost layer of the skin, comprised of several distinct layers, each playing unique roles in skin health and function. The layer consisting of flattened, dead cells that have undergone a process called keratinization is the stratum corneum.

As this outermost layer, the stratum corneum is primarily made up of keratinocytes, which have lost their nuclei and are filled with keratin, a tough protein that aids in providing a protective barrier for the underlying layers of skin. These cells are tightly packed and overlap, forming a resilient and water-resistant shield that helps defend against environmental hazards, pathogens, and water loss.

This layer is crucial for the overall function of the skin, as it provides physical protection and plays a significant role in preventing dehydration. With these dead skin cells continuously sloughing off and being replaced by cells from the deeper layers of the epidermis, the stratum corneum constantly renews itself, maintaining the health of the skin.