What is the dermis?
The dermis (corium) is the middle of the three layers that make up our skin. It lies under the epidermis and above the subcutis. The dermis consists of connective tissue fibers and is divided into two layers, which are not sharply demarcated from each other, but rather merge into each other:
- Stratum papillare: the outer layer adjacent to the epidermis.
- Stratum reticulare: the inner layer
What is the function of the dermis?
The dermis function is to anchor the epidermis. In addition, the dermis supplies the epidermis with nutrients (the epidermis itself has no vessels).
Stratum papillare
The stratum papillare consists of loose connective tissue and contains, among other things, many capillaries (fine blood vessels). If there is a problem with the venous return of the blood, then enlarged veins appear here as spider veins.
The stratum papillare is also where most of the skin’s sensory cells for touch and vibration perception are located. Defense cells can move freely in this layer.
Stratum reticulare (reticular layer)
The direction of the fiber bundles determines the so-called cleavage lines of the skin: If the skin is injured along a cleavage line, the wound does not gape apart. However, if the wound runs across a cleavage line, it gapes apart. Surgeons use these cleavage lines to achieve the most inconspicuous scar formation possible.
Sebaceous glands
The sebaceous glands produce the sebum that keeps the skin supple. You can read more about them in the article Sebaceous glands.
Sweat glands
Sweat production contributes to heat regulation. In addition, a small amount of those substances can be released via sweat that can otherwise only be excreted via the kidneys (such as common salt).
What problems can the dermis cause?
If the venous return of the blood is disturbed, spider veins can develop in the dermis.
Due to a backlog of secretions in the excretory ducts of the sebaceous glands, so-called blackheads (comedones) form. In acne vulgaris, the sebaceous glands are inflamed.
The dermis can lose moisture with age, making the epidermis less firm.
