Collagen fibers provide structural support for the tissues in the human body. They are also found in the extracellular matrix that helps cells maintain their structure.
Dr. Anne Marie Helmenstine says collagen is the most common protein in humans. Collagen fibers, along with keratin, make the skin strong and waterproof. Skin elasticity is also due to the presence of collagen fibers and keratin, and wrinkles form when there is less collagen available to support the skin.
Collagen fibers are also found in connective tissue. This type of tissue supports muscle tissue, nerve tissue and epithelial tissue. The functions of connective tissue include nutrient transport and inflammation, according to experts from Southern Illinois University School of Medicine.