What characterizes the stratum spinosum?

The stratum spinosum is primarily characterized by its multiple layers of keratinocytes that have a spiny appearance due to desmosome connections between adjacent cells. This layer provides strength and flexibility to the skin, playing a crucial role in the overall structure of the epidermis. The keratinocytes in the stratum spinosum are not dead; they are living cells that are actively participating in the process of keratinization, which eventually leads to the formation of the outermost layer of the skin.

The correct representation of the stratum spinosum should focus on its role as a supportive layer filled with cells that are still metabolically active, rather than dead or flat cells. Each of the incorrect options fails to accurately describe this layer. The presence of stratified cuboidal cells applies more to specific glandular tissue rather than to the epidermis, while the descriptions that focus on dead cells or flat, keratinized cells pertain more to layers like the stratum corneum and do not accurately reflect the characteristics of the stratum spinosum.