Massachusetts State Board Esthetics Practice Exam

What is the composition of cells in the stratum spinosum?

1. Clear, dead cells

2. Cells continuously dividing and changing shape

3. Granule-filled cells

4. Dead keratinocytes

The correct answer is: Cells continuously dividing and changing shape

The stratum spinosum, often referred to as the "spiny layer," is characterized by its composition of living keratinocytes that are actively processed as they move up through the layers of the epidermis. In this layer, the cells demonstrate a polygonal shape and have a higher degree of intercellular connections, giving them a spiny appearance under a microscope. These keratinocytes are not only continuously dividing but also begin to change in shape as they mature and prepare to move to the upper layers of the skin. This dynamic process is crucial for the overall structure and function of the skin, as it contributes to the formation of the skin barrier. The other options do not accurately reflect the nature of the cells in the stratum spinosum. Clear, dead cells are more characteristic of the stratum corneum, the outermost layer, while granule-filled cells are typically found in the stratum granulosum. Dead keratinocytes also primarily belong to the more superficial layers of the epidermis and are not representative of the stratum spinosum, which is still largely comprised of living cells that are integral to skin health and regeneration.