Final answer:
A needle piercing the forearm's epidermal layers would pass through the stratum corneum, stratum granulosum, stratum spinosum, and finally the stratum basale. The correct option is C.
Step-by-step explanation:
A needle would pierce the epidermal layers of the forearm in the following order:
- Stratum corneum
- Stratum lucidum (only present in thick skin, such as on the palms of hands and the soles of feet)
- Stratum granulosum
- Stratum spinosum
- Stratum basale
The stratum corneum is the outermost layer that consists of dead cells and serves as a barrier to protect the underlying tissue.
Proceeding inwards, if the skin is thick, the needle would pass through the stratum lucidum, which is not present in thin skin like that of the forearm.
Following this layer, the needle would then move through the stratum granulosum where keratinocytes begin to die, then the stratum spinosum, which is thicker and has spiny keratinocytes, and finally, the stratum basale, which is the deepest layer that attaches to the basement membrane and contains stem cells that divide to form new keratinocytes. The correct option is C.