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

Which structure is part of the epidermis?

1. Stratum granulosum

2. Subcutaneous tissue

3. Muscle fascia

4. Bone

The correct answer is: Stratum granulosum

The stratum granulosum is indeed a part of the epidermis, which is the outermost layer of the skin. This specific layer plays a crucial role in the skin's protective function. It is situated above the stratum spinosum and below the stratum lucidum in thick skin. The cells in the stratum granulosum are characterized by their granular appearance, as they contain keratohyalin granules that contribute to the process of keratinization. These granules help in the formation of a waterproof barrier, which is essential for preventing water loss from the body and protecting against external environmental factors. In contrast, the subcutaneous tissue, muscle fascia, and bone do not belong to the epidermis. The subcutaneous tissue is found beneath the dermis and provides insulation and cushioning for the body. Muscle fascia surrounds muscles and groups of muscles, providing support and facilitating movement, whereas bone is a dense connective tissue that makes up the skeleton. Understanding the distinct roles and locations of these tissues is important in differentiating them from the structures that comprise the epidermis.