The dermis is the second layer of skin in our bodies. It is comprised mostly of water, elastic fibers, and other important structures that serve to support the skin.
The epidermis is the outmost layer of visible skin. The cells in the epidermis have undergone keratinization and have hardened. Keratinization is also the same process that causes hair to mature and prepare for shedding.
Just below the epidermis is an even thicker layer called the dermis. Cells at this level are alive and divide rapidly. They are eventually pushed to the surface so that they may undergo keratinization as well.
The dermis contains the following characteristics:
Dermal fibroblasts are the primary types of cells found in this layer of skin. They are found in much greater abundance at the higher levels of the dermis, and hardly at all in the lower levels. Although these cells do not change into other cell types, they are responsible for producing collagen (with the help of keratinocytes) and other crucial elastin fibers.
When it comes healing the skin from injury, fibroblasts play a critical role. They are what directs the collagen to regrow over the wound, and they are also what signals a new migratory path for the blood vessels to take immediately after a wound occurs.
Stem cells can be considered “blank cells”, or cells that can transform into whatever type of cell is necessary to heal an injury. Fibroblasts produce certain kinds of proteins that can help stabilize and improve the survivability of stem cells. For this reason, dermal fibroblast cells are often removed from the body’s tissue and cultivated with stem cells. Dermal fibroblasts can even become stem cells themselves, though their uses are limited.