Final answer:
The hypodermis is not considered part of the skin; it is the layer beneath the dermis and contains connective tissue and fat.
Step-by-step explanation:
The layer that is NOT considered part of the skin is d. hypodermis. The skin is primarily made up of two layers: the epidermis and the dermis. The epidermis itself consists of several layers, starting with the stratum basale (also known as the stratum germinativum), followed by the stratum spinosum, stratum granulosum, and sometimes stratum lucidum, and then finally the outermost layer, the stratum corneum. The hypodermis, also known as the subcutaneous layer, lies below the dermis and is not technically considered part of the skin. It contains connective tissue, fat cells, and large blood vessels, serving as insulation and as a padding layer for the skin.