What is the outermost layer of the epidermis?

The outermost layer of the epidermis is the stratum corneum. This layer consists of dead keratinized cells that provide a strong and protective barrier against environmental factors such as pathogens, chemicals, and physical abrasion. The cells in the stratum corneum are continuously shed and replaced, making this layer crucial for maintaining the overall health and integrity of the skin.

In contrast, the stratum spinosum is located below the stratum corneum and contains several layers of keratinocytes that provide strength and flexibility to the skin. The stratum granulosum, also beneath the stratum corneum, plays a role in the keratinization process and is where keratinocytes begin to lose their nuclei and become more flattened. The stratum basale is the deepest layer of the epidermis and is responsible for generating new skin cells through mitosis. Each of these layers has its own specific function and contributes to the overall structure and function of the epidermis, but the stratum corneum is specifically designed as the outer protective covering.