Collagen and elastin are two proteins that form fibers to help make up connective tissue in the body. Collagen is widespread in the body and gives connective tissue strength and flexibility. Elastin is a protein that returns to its original shape after being stretched. While collagen occurs more widely in the body, both it and elastin are necessary for the function of many tissues.
Collagen is so anatomically prevalent that it accounts for a third of the body's total protein. This is about 6% of the total weight of the body. In the body, collagen forms collagen fibers that make up ligaments and tendons, cartilage, skin and bone tissue. There are about 20 types of collagen, with some types being specific to certain tissues or organs. Other types of collagen support organs or take up the space between organs and tissues. Collagen occurs in strong and flexible collagen fibers.
Elastin, as its name implies, is a protein with an elastic quality. It will return to its original state after stress, whether it is compressed or stretched. Elastin fibers form networks like collagen. Tissues gain elasticity when they contain elastin.
Both collagen and elastin are notable for their roles in aging. As the body ages, collagen proteins become more cross-linked and rigid. Collagen is important for strength, but tissues like the lens of the eye can become overly rigid and lead to vision problems. Decreasing production of elastin and collagen in the skin leads to wrinkles or leathery skin.
Vitamin C is necessary for the the formation and organization of collagen fibers. Scurvy, which is caused by Vitamin C deficiency, causes symptoms such as poor wound healing and blood vessel hemorrhage. The teeth can even fall out because the ligaments that hold the teeth in their sockets become weakened.
Both collagen and elastin occur in the important extracelluar matrix, which is made up of loose connective tissue, known in this case as areolar. This type of tissue surrounds almost all of the capillaries or small blood vessels in the body. Nutrients from the blood pass through the fluid of the extracelluar matrix to support the cells of the body. Thus, no cell lies far from the connective tissue formed from collagen and elastin. The structure of the extracelluar matrix also supports the functionality of tendons to withstand being stretched, the bones to bear weight, and the ability of skin to withstand injury.