Dermis

This is a layer of the skin that is referred to as either the dermis or the corium, It is located under the skin in between the epidermis and the subcutaneous tissues, which is mainly connective tissue that is dense and irregular. This is the area which acts as a cushion for the human body, adding additional protection from stress, strain and external elements. When broken down, it can be divided into two separate layers, first the superficial area which is adjacent from the epidermis. This is referred to as the papillary region. Then there is the reticular dermis, which is a deeper and thicker area. It is connected very tightly with the epidermis by way of the basement membrane. Its structural components are the elastic fibers; collagen; and the extra-fibrillar matrix. It also consists of mechan-o-receptors which help in providing the body a sense of there being heat, including sweat glands; apocrine glands; blood vessels; hair follicles; sebaceous glands (these are the oil glands); lymphatic vessels; and nerves. The blood vessels mentioned above are the means of nourishment, as well as how the waste is removed for both of the cells.

The structure

There are three significant cell types which create this part of the body, they are the macrophages, adipocytes, and the fibroblasts. Other than these cells, there are also some matrix components, including elastin, this gives the body its elasticity; collagen, this gives the body its strength; proteoglycans; glycoproteins; extrafibrillar matrix, which has a substance that is like a gel and is mainly created of glycosaminoglycans, more notably as being hyaluronan.

The Layers

Papillary

The papillary is the most important layer of the dermis. It is made of fine collagen and the collagen fibers are loosely arranged and is intertwining with the rete ridges in the epidermis. The papillary region is made from the loose areolar connective tissue. Its name comes from its finger like projections referred to as papillae, and extends facing the epidermis, and it consist of one or the other, the terminal networks of the blood capillaries, including the tactile Meissner’s corpuscles.

Reticular

This is the lowest layer; it is located beneath the papillary and is made from dense irregular connective tissue which features collagen fibers that are densely packed. It is also the main location for the dermal elastic fibers. The reticular region is generally a lot thicker than its overlying papillary. It gets the name from the dense concentration that is in the collagenous; reticular fibers; elastic, that are all weaved all through it. It is the protein fibers which give it its properties of strength; elasticity; blood vessels; and its extensibility. Inside the reticular area is the sebaceous glands; the roots of the hair; receptors; nails; blood vessels; and sweat glands. Lines are causing tension to be created by the collagen fibers of the reticular which is referred to as Langer’s lines, and these show some relevance during surgery and the healing time of the wound.

Dermal papillae

The dermal papillae are little nipple extensions going to the epidermis. Appearing as papillary ridges on the skin surface of the hands and feet, also known as fingerprints.

Hair follicles get their nourishment from the blood vessels of the dermal papillae, and nutrients, as well as oxygen are brought from them and taken to the lowest layers in the epidermal cells. The ridges produced in the hands and feet have patterns have determined features that have been developed prior to birth, thus, they are partly genetic. These remain substantially the same throughout a person’s life, so therefore, this determines what the patterns are going to be, such as finger prints, and these are beneficial in specific functions and for personal identification. As a part of the most important layer, the dermal papillae and the ridges form by them increases the size of the area located between the epidermis and the dermis. This is due to the primary function of supporting the epidermis, for this increases the need to exchange oxygen and nutrients, including waste products in the middle of these two layers. In addition, due to the increase of the surface area it is preventing both, the epidermal and the dermal layers from detaching from one another because they are being strengthening the junction of the two. The papillae will become flat with age and often increase in numbers. The dermal papillae play a role in the growth and the hair formation.

Whereas the epidermis is made up of four to five layers, which depends on the area to be considered. Below is a list of the layers in a descending order.

Individual Layers

When you really break things down, there are five layers to our skin that vary between the most superficial (surface) to the deepest.

Stratum Corneum

This is the outer surface area which is mostly shed dead skin cells that are released back into the surrounding environment. Because of this, dust that collects around the home typically contains these cells. Additionally, this is the layer that aids in repelling water.

Stratum Lucidum

Located only on the bottom of our feet, hands and fingertips.

Stratum Granulosum

Keratin is produced within this layer, which is a protein and a major element that aids in skin health.

Stratum Spinosum

This is the second deepest section, which provides the flexibility and strength.

Stratum Basale

Finally, we hit the very last layer, the Basale. In this section, the most significant cells are found – they are known as keratinocytes. Over time the body naturally rejuvenates skin, generally around every 30 days or so. This occurs as the keratinocytes do their job, then transition from the Basale to the Spinosum, eventually reaching the Corneum and becoming dust in the environment.

Additionally, the bottom layer is where melanocyte cells develop, which are greatly connected to protecting skin against sun damage and determining pigmentation color.