Utah Esthetics Written State Practice Exam

In which layer of the skin do desmosomes primarily function?

1. Stratum corneum

2. Stratum granulosum

3. Stratum spinosum

4. Stratum basale

The correct answer is: Stratum spinosum

Desmosomes primarily function in the stratum spinosum, which is the second layer of the epidermis. This layer is where keratinocytes are connected by desmosomes, which are specialized cell structures that provide strong adhesion between cells. This adhesion is crucial for maintaining the structural integrity of the skin, especially in areas subjected to mechanical stress. In the stratum spinosum, cells appear spiky due to these desmosomal connections, which help resist abrasion and protect underlying tissues. The presence of desmosomes in this layer contributes significantly to the overall strength and resilience of the epidermis, allowing it to function effectively as a barrier against environmental factors. The other layers mentioned each have distinct structural and functional characteristics. For instance, the stratum corneum is primarily made up of dead keratinocytes that do not contain desmosomes, as they have already lost their connections and are in a protective layer. The stratum granulosum contains keratin-producing cells that are in a transition phase towards dying and becoming part of the stratum corneum. The stratum basale, being the deepest layer, consists mainly of proliferating keratinocyte stem cells where the attachment is primarily to the basement membrane rather than between individual