Typically the dermis or corium is actually a layer of skin involving the epidermis (with which that forms the skin) plus the subcutaneous tissue, which is composed mainly of dense unusual connective tissue and absorbs the body from stress and tension.


It is divided into two layers, the surface area adjacent to the epidermis is called the papillary region and the deeper area known as reticulate skin. The dermis is closely connected to the epidermis through the basal membrane. The structural components of the dermis are collagen, elastic fibers and a matrix in the form of fibers. Read below dermis function.



Dermis function


Papillary dermis


The papillary skin is the highest layer of the dermis. Intertwined with the backs of the epidermis and consists of small and loosely arranged collagen fibers. The papillary region consists of loose connective tissue. The name comes from its finger-like projections called warts that extend towards the epidermis and contain either the terminal capillary networks or the tactile Meissner body.


Reticulate skin


Reticulated skin is the lower layer of the dermis, located under the papillary skin, composed of dense, irregular connective tissue with densely packed collagen fibers. This is the main location for flexible skin fibers.


The mesh region is usually much thicker than the above-lying papillary skin. It owes its name to the dense concentration of collagen, elastic and mesh fibers that intertwine in it. These protein fibers give the dermis proper strength, stretchability and elasticity.


Within the reticulate, there are roots of the hair, sebaceous glands, sweat glands, receptors, nails, and blood vessels. The orientation of collagen fibers in the reticular skin forms tension lines called Langer’s lines, which have some significance in surgery and wound healing.



Dermal papillae


The dermal papillae (DP) (singular papilla, diminutive of Which include papula, ‘pimple’) are smaller than average nipple-like extensions (or interdigitations) of the dermis directly into the epidermis. At the surface of hands and feet, they appear as epidermal or papillary ridges (colloquially known as fingerprints).


Blood cells in the dermal papillae nourish all hair follicles and bring oxygen to the layers of epidermal cells. The dermal papillae are part of the uppermost layer of the dermis, the papillary dermis, and the ridges of the dermis and epidermis.


Since the primary function of the particular dermis is to assistance the epidermis, this significantly increases the exchange associated with oxygen, nutrients, and waste materials. Addiction, the increase in the surface of the dermal and epidermal layers of the junction between them.


Dermal papillae also play a pivotal role in curly hair formation, growth.  In mucous membranes, the corresponding structures are dermal papillae are generally termed “connective tissue papillae”, which interdigitate with the rete pegs of the superficial epithelium.