Collagen is the most abundant protein in the human body, accounting for a third of all the protein in the body. It is considered mainly a structural protein in that it provides support for connective tissue in the body, such as that in skin, muscles, and bone. It is also the primary protein in tendons and ligaments. But besides these tissues, collagen also exists in blood vessels, the cornea of the eye, and even in your teeth. The extracellular matrix is a large network of proteins and other molecules that surround, support, and give structure to cells and tissues in the body. The extracellular matrix helps cells attach to, and communicate with, nearby cells, and plays an important role in cell growth, cell movement, and other cell functions. The extracellular matrix can be looked at as the stuff that holds cells together, a type of biological glue, and it's composed largely of collagen. As for tendons and ligaments, 65 to 85% of the dry weight of tendons and ligaments is composed of collagen. It is the cross-linked structure of collagen in tendons and ligaments that provides strength in these structures.
Collagen contains high amounts of three amino acids: glycine, proline, and hydroxyproline. Depending on what source you read there are anywhere from 16 to 28 different types of collagen. But there are four main types found in the human body. These are the following:
- Type I. This type accounts for 90% of your body’s collagen and is made of densely packed fibers. It provides structure to skin, bones, tendons, fibrous cartilage, connective tissue, and teeth.
- Type II. This type is made of more loosely packed fibers and is found in elastic cartilage, which cushions your joints.
- Type III. This type supports the structure of muscles, organs, and arteries.
- Type IV. This type helps with filtration and is found in the layers of your skin.
Collagen loss in the body begins between the ages of 18 and 29 and beginning at age 40 the body loses an average of 1% collagen a year. The level of collagen in the body of a person 80 years old is 75% less than that of younger adults. There are other factors contributing to this such as free radicals, deficient diet, smoking, alcoholism, and disease. The role of collagen in the body is very important because it helps the development of the organs; wound and tissue healing; cornea, gums, and scalp repair. Collagen helps in bone and blood vessel repair. In the cornea, collagen tissue has mechanical and optical properties. It's present in biological functions of the cell such as proliferation, cell survival, and differentiation; so collagen is present in the human body as a whole in bones, tendons, ligaments, hair, skin, and muscles.
One of the more obvious signs of a loss . . .
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