The dermis is the middle layer of the skin and is responsible for water
binding, wound repair, and diffusion regulation involving hormones, salts,
and other metabolic substances. It contains pain and touch receptors,
whose tentacles reach up to the skin surface, and many of the functional
glands of the skin: sweat glands, sebaceous glands (which produce the oil
sebum to help moisturize the skin), and hair follicles. Also within the
dermis lie blood vessels that provide nutrition to the skin and nerves that
branch throughout the layers of the skin.
Important components of the dermis and their function include:
The dermis is held together by a fibrous insoluable protein called
collagen which is the most abundant protein in the body. Elastin is
a protein substance that forms the principal constituent of yellow
elastic tissue and gives the skin itís resiliency and feel.
Glycosaminoglycans (GAGs) produce a highly hydrated, gel-like
matrix that helps to maintain water balance, and act as a support
system for the components of the dermis. Hyaluronic acid and
chondroitin sulfate (found in cartilage and bone) are
Fibroblasts are responsible for producing collagen, elastin, and
A blood supply is necessary to transport nutrients to the normally
functioning skin and to remove waste products generated through
cellular metabolism. An adequate blood supply must be present.
The blood vessels present are the arterioles which bring
oxygenated blood from the heart and lungs; veinules which return
oxygen-depleted blood back to the heart and lungs; and capillaries
which are the primary sites for exchange of oxygen and nutrients.