Which type of cell is the predominant type in the stratum spinosum? \( \begin{array}{llll}\text { a. Merkel } & \text { b. Langerhans } & \text { c. Melanocyte } & \text { d. Keratinocyte }\end{array} \)

The predominant cell type in the stratum spinosum is d. Keratinocyte. These cells are crucial for providing strength and resilience to the skin, as they produce keratin, a fibrous protein that helps protect the underlying layers and maintain the skin's barrier function. As cells in the stratum spinosum mature, they begin to change shape and form connections with neighboring cells, creating a spiny appearance, hence the name "spinosum." This layer plays a key role in the skin's overall health and functionality, making it an important area for protecting against environmental damage!