Which statement about the Stratum Corneum is true?

Which statement about the Stratum Corneum is true?

• A. It contains living cells with nuclei
• B. It is approximately 15-20 cell layers thick and generates NMF essential for pH balance
• C. It is the site of keratinocyte mitosis
• D. It is the deepest layer of the epidermis

Answer: (B)

The Stratum Corneum is the outermost epidermal layer made of dead, flattened keratinocytes (corneocytes) held together by lipids. Because these cells are nonliving, they don’t contain nuclei or divide, so mitosis happens in the deeper stratum basale, not here. The layer’s thickness can be about 15-20 cell layers in many areas, especially in thicker skin, though it varies by body site. It also contains the processes that generate natural moisturizing factor (NMF) from the breakdown of filaggrin in corneocytes, which helps hydrate the skin and maintain a mildly acidic pH. So describing the stratum corneum as roughly 15-20 cell layers thick and involved in producing NMF for pH balance is the true statement.

The Stratum Corneum is the outermost epidermal layer made of dead, flattened keratinocytes (corneocytes) held together by lipids. Because these cells are nonliving, they don’t contain nuclei or divide, so mitosis happens in the deeper stratum basale, not here. The layer’s thickness can be about 15-20 cell layers in many areas, especially in thicker skin, though it varies by body site. It also contains the processes that generate natural moisturizing factor (NMF) from the breakdown of filaggrin in corneocytes, which helps hydrate the skin and maintain a mildly acidic pH. So describing the stratum corneum as roughly 15-20 cell layers thick and involved in producing NMF for pH balance is the true statement.