Wound, Ostomy and Continence Nurses Society (WOCN) Practice Exam

What is the primary component of the stratum corneum?

1. Collagen fibers

2. Keratin

3. Melanin

4. Elastic fibers

The correct answer is: Keratin

The primary component of the stratum corneum is keratin. This outermost layer of the epidermis serves a critical role in protecting the underlying layers of skin from external factors, such as pathogens, chemicals, and physical injury. Keratin is a fibrous protein that provides structural strength and waterproofing properties, which is essential for maintaining skin integrity and function. While collagen fibers, melanin, and elastic fibers are important components of the skin, they are not found primarily in the stratum corneum. Collagen fibers are primarily located in the dermis, providing strength and support. Melanin, responsible for pigmentation, is produced by melanocytes which are found in deeper layers of the epidermis, not predominantly in the stratum corneum. Elastic fibers are also situated in the dermis, contributing to skin elasticity and flexibility. Therefore, keratin stands out as the defining component of the stratum corneum, emphasizing its role in skin barrier function.