Dermis

The dermis ( to Greek derma "skin" ) is a layer of the skin of vertebrates. It serves to anchor and the nutrition of the avascular epidermis.

The German name dermis ( corium Latin ) based on the fact that leather can be produced by tanning from this skin layer.

Construction

The dermis contains tear-resistant collagen fibers and elastic fibers. In addition, numerous blood and lymphatic vessels are woven into the dermis. The skin glands and hair roots lie mainly within the dermis and also the most sensory receptors of the skin are also located in this layer.

The elastic fibers are responsible for the suppleness and flexibility of the skin. At the age this elasticity is stark. In addition, the tension of the fiber bundle cause the edges of the wound gape in injuries to the skin apart.

The main direction of collagen fiber bundles is denoted by the term cleavage lines. Wounds in the direction of the nip lines gape less than transverse. This fact, the surgeon tries to exploit, in which it places its cuts along the split lines.

Papillary

The rich in capillaries fabric which is most pronounced in the teenage years, also determines the folding of the dermal- epidermal junction zone ( DE junction). The transition zone is mechanically for better fixation of the two layers. When venous return defects appear enlarged veins, to so-called spider veins.

In papillary sit most of the sensory cells of the skin. The intercellular spaces are filled with a jelly-like far and liquid ( interstitium ), which is drained by the lymphatic system begins here. Different cells can move fairly freely in this tissue. There are primarily immune cells such as macrophages, lymphocytes, plasma cells, mast cells, granulocytes and monocytes but also to find the connective tissue -forming cells ( fibroblasts).

Between dermis and epidermis runs an undulating to peg-shaped boundary, called the papillary layer. The multiple indentations of the sclera in the base of the epidermis results in a large surface area and thus firm mechanical connection of the two layers and to facilitate the release of nutrients to the epidermis.

The papillary layer is relatively flat papillae in hairy skin sections, as well as the hairs involved in the anchoring of the epidermis.

Stellate reticulum / texticulare

In the reticular layer (network layer) is tight, braid -like connective tissue is collagen fibers ( type I) and accompanying elastic fibers. The liquid fraction in this layer determines the firmness of the skin.