What is the horny layer of the epidermis composed of plate-like cells filled with keratin called?

The horny layer of the epidermis, known as the stratum corneum, is the outermost layer and is primarily made up of dead skin cells that are flattened and filled with keratin. This layer serves as a crucial barrier, protecting the underlying layers of the skin from environmental damage, moisture loss, and pathogens. The keratin within these cells gives the skin its strength and resilience, making it a vital component in the overall function of the skin.

The stratum lucidum is a thin, translucent layer found beneath the stratum corneum, primarily located in areas of thick skin, such as the palms and soles. It consists of a few rows of clear, dead keratinocytes.

The term "epidermis" refers to the entire outer layer of the skin, which includes all the sublayers of the epidermis, not just the horny layer.

Lastly, the stratum granulosum is located beneath the stratum corneum and contains keratinocytes that are transitioning to the surface, but it does not represent the outermost layer that primarily serves as a protective barrier filled with keratin.

Understanding this hierarchy and composition of skin layers helps in recognizing the role each section has in skin physiology and health.