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Basement membrane[edit]

Main article: Basement membrane
The epidermis and dermis are separated by a thin sheet of fibers called the basement membrane, which is made through the action of both tissues. The basement membrane controls the traffic of the cells and molecules between the dermis and epidermis but also serves, through the binding of a variety of cytokines and growth factors, as a reservoir for their controlled release during physiological remodeling or repair processes.^[15]

Dermis[edit]

Main article: Dermis
The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis provides tensile strength and elasticity to the skin through an extracellular matrix composed of collagen fibrils, microfibrils, and elastic fibers, embedded in hyaluronan and proteoglycans.^[14] Skin proteoglycans are varied and have very specific locations.^[16] For example, hyaluronan, versican and decorin are present throughout the dermis and epidermis extracellular matrix, whereas biglycan and perlecan are only found in the epidermis.
It harbors many mechanoreceptors (nerve endings) that provide the sense of touch and heat through nociceptors and thermoreceptors. It also contains the hair follicles, sweat glands, sebaceous glands, apocrine glands, lymphatic vessels and blood vessels. The blood vessels in the dermis provide nourishment and waste removal from its own cells as well as for the epidermis.
Dermis and subcutaneous tissues are thought to contain germinative cells involved in formation of horns, osteoderm, and other extra-skeletal apparatus in mammals.^[3]
The dermis is tightly connected to the epidermis through a basement membrane and is structurally divided into two areas: a superficial area adjacent to the epidermis, called the papillary region, and a deep thicker area known as the reticular region.