Final answer:
The dermis is the inner layer of skin beneath the epidermis, containing two layers: the papillary and reticular layers. The papillary layer's projections, or papillae, extend into the epidermis creating epidermal ridges, like fingerprints, which are unique to individuals. The epidermis is the protective outer layer of the skin, thinner in comparison to the dermis.
Step-by-step explanation:
The Dermis and Epidermis of the Skin
The student's question relates to the structure of the skin, particularly the dermis and the epidermis. The dermis is the thicker, inner layer of the skin that lies beneath the epidermis and contains structures such as blood vessels, hair follicles, and sweat glands. It is mainly made of tough connective tissue, which provides strength and elasticity to the skin. Within the dermis, there are two distinct layers: the superficial papillary layer and the deeper reticular layer. The papillary layer is notable for its projections called papillae that extend upward into the epidermis, giving it a bumpy surface and strengthening the connection between the dermis and epidermis. These papillae are responsible for the creation of epidermal ridges, commonly recognized as fingerprints, which are unique to each individual and can serve as a means of identification.
Contrary to the question's suggestion, the epidermis does have ridges (due to the papillae of the dermis), but overall, the epidermis is thinner than the dermis. The epidermis is the outermost layer of skin, composed of keratin-filled cells, and lacks a blood supply, serving as a protective barrier. The dermis, in comparison, is highly vascularized and contains sensory receptors, enabling it to detect touch, pressure, and temperature changes.