Which of the following is NOT one of the three layers of skin?

The stratum corneum is actually part of the epidermis, which is one of the three primary layers of the skin. While the stratum corneum is the outermost layer of the epidermis, it does not represent a standalone layer of skin. Instead, the three main layers of skin are the epidermis, dermis, and subcutaneous layer.

The epidermis is the top layer, responsible for providing a barrier and skin tone, while the dermis beneath it contains connective tissue, hair follicles, and sweat glands. The subcutaneous layer, also known as the hypodermis, is the innermost layer that helps insulate the body and absorb shocks. Recognizing that the stratum corneum is part of the epidermis is crucial for understanding skin structure and function, making it clear why identifying it as a separate layer is incorrect.