Massachusetts State Board Esthetics Practice Exam

What is a significant function of the stratum granulosum layer?

1. Production of new skin cells

2. Barrier to external elements

3. Keratin and lipid production

4. Melanin production

The correct answer is: Keratin and lipid production

The stratum granulosum is a critical layer of the epidermis that plays a significant role in skincare and skin health. One of its primary functions is the production of keratin and lipids. Keratin is a valuable protein that helps to provide structure and strength to the skin, while lipids create a moisture barrier that prevents water loss. This dual production contributes to the overall integrity and hydration of the skin. In this layer, keratinocytes undergo a process of keratinization, where they flatten and begin to lose their nuclei, eventually becoming part of the outer protective barrier of the skin. The lipids produced in this layer aid in maintaining the skin’s barrier function, essential for protecting against external aggressors like bacteria, pollutants, and harmful UV radiation. While the stratum granulosum does contribute to the barrier function and plays a role in the skin renewal process, its standout contribution is specifically tied to the production of keratin and lipids, which are crucial for the skin's ability to retain moisture and remain resilient against environmental challenges.