What type of skin layer is involved in the prickly or spiny appearance of cells?

The stratum spinosum is the correct choice because this layer of the epidermis is characterized by the presence of desmosomes, which are intercellular connections that create a spiny or prickly appearance to the cells under a microscope. These desmosomes help to provide structural support and cohesion between the cells. Additionally, the cells in the stratum spinosum begin to flatten as they move towards the surface of the skin, which further contributes to this appearance. This layer also plays an essential role in the skin's protective barrier functions.

In contrast, the stratum corneum is the outermost layer and is primarily made up of dead, flattened keratinocytes that do not have the spiny structure. The stratum granulosum is where keratinocytes begin to undergo keratinization, and while it has granular cells, it does not exhibit the prickly appearance. The stratum reticulare is part of the dermis, not the epidermis, and therefore does not relate to the characteristics of the skin layers you asked about. Understanding these differences highlights the functional and structural diversity of the skin's layers, particularly the significance of the stratum spinosum in providing a more resilient surface.