Which layer of the epidermis is responsible for replacing cells shed from the stratum corneum?

• A. Stratum basale
• B. Stratum granulosum
• C. Stratum lucidum
• D. Stratum spinosum

Answer: (B)

The stratum granulosum plays a key role in the process of keratinization and the overall health of the epidermis. This layer contains keratinocytes that begin to flatten and accumulate keratin, transitioning from living cells to dead cells as they move towards the surface. While the stratum basale is responsible for the proliferation of new cells, and the stratum spinosum serves to provide strength and support to the skin, it is the stratum granulosum that specifically prepares these cells to ensure that as the outermost layers, such as the stratum corneum, lose cells through shedding, new cells are produced and filled with keratin ready to take their place. This function is crucial for maintaining the barrier and protective roles of the skin. As such, the distinction of the stratum granulosum in linking the inner layers of the epidermis to the outer protective layer makes it essential in replacing cells shed from the stratum corneum.