What is commonly known as "true skin" or "cutis"?

The term "true skin," or "cutis," refers specifically to the dermis, which is the layer of skin located beneath the epidermis. The dermis is responsible for providing strength and elasticity to the skin, as it contains connective tissues, blood vessels, nerve endings, and appendages such as hair follicles and sweat glands.

In contrast, the epidermis is the outermost layer of skin that provides a barrier and protection against environmental factors. While it is essential for overall skin health, it does not contain the structural features or functions attributed to the dermis, thus distinguishing the two layers. The hypodermis, also known as the subcutaneous layer, is found below the dermis and consists mostly of fat and connective tissue, serving primarily as insulation and energy storage, rather than providing the same structural role as the dermis.

In summary, the dermis is rightly termed "true skin" because it contains the vital components that contribute to the skin's resilience and functionality, making it integral to the overall structure of the skin.