Wisconsin Esthetics State Board Practice Test

Which skin layer is primarily responsible for protection and is composed of keratinocytes?

1. Dermis

2. Subcutaneous

3. Epidermis

4. Stratum corneum

The correct answer is: Epidermis

The epidermis is primarily responsible for protecting the body from environmental hazards and is the outermost layer of the skin. It is predominantly composed of keratinocytes, which are skin cells that produce keratin, a protein that forms a protective barrier and is essential for maintaining the skin's integrity. The keratinocytes in the epidermis continuously shed and regenerate, providing a resilient surface that helps prevent moisture loss and shields against pathogens, UV radiation, and other external elements. While the stratum corneum, which is the outermost layer of the epidermis, also plays a significant role in protection by providing a barrier made primarily of dead keratinocytes, it is just one component of the larger epidermis. The dermis and subcutaneous layers, although also important for the skin's overall function and health, do not fulfill the primary protective role attributed to the epidermis.