Which epidermal layer forms the boundary with the dermis?

Which epidermal layer forms the boundary with the dermis?

• A. Stratum Basale
• B. Stratum Spinosum
• C. Stratum Granulosum
• D. Stratum Corneum

Answer: (A)

The boundary with the dermis is formed by the deepest layer of the epidermis resting on the basement membrane. This layer is a single row of keratinocytes that sit directly on the basement membrane and proliferate to renew the epidermis. They attach to the basement membrane via hemidesmosomes, anchoring the epidermis to the underlying dermis. The basement membrane is produced at this interface and serves as the junction between the two skin layers. The layers above it—the spinosum, granulosum, and corneum—do not contact the dermis directly, with the corneum being the outermost, dead protective layer.

The boundary with the dermis is formed by the deepest layer of the epidermis resting on the basement membrane. This layer is a single row of keratinocytes that sit directly on the basement membrane and proliferate to renew the epidermis. They attach to the basement membrane via hemidesmosomes, anchoring the epidermis to the underlying dermis. The basement membrane is produced at this interface and serves as the junction between the two skin layers. The layers above it—the spinosum, granulosum, and corneum—do not contact the dermis directly, with the corneum being the outermost, dead protective layer.