Pennsylvania Esthetician State Board Practice Exam

What is the outermost layer of the epidermis known as?

1. Stratum Granulosum

2. Stratum Corneum

3. Stratum Basale

4. Stratum Spinosum

The correct answer is: Stratum Corneum

The outermost layer of the epidermis is known as the Stratum Corneum. This layer is primarily composed of dead keratinized cells that provide a protective barrier for the underlying layers of the skin. The Stratum Corneum is essential for preventing water loss and protecting the body from environmental damage, such as pathogens and chemicals. The keratin in this layer helps to provide strength and resilience, allowing the skin to resist abrasion and injury. In contrast, the other layers mentioned, such as the Stratum Granulosum, Stratum Basale, and Stratum Spinosum, are located deeper in the epidermis and have different functions. The Stratum Granulosum is where the process of keratinization begins, the Stratum Basale is responsible for the generation of new skin cells, and the Stratum Spinosum provides strength and flexibility to the skin. Understanding the structure and function of the Stratum Corneum emphasizes its role in overall skin health and integrity.