Tendon

From ArticleWorld

A tendon is a tough band of connective tissue that begins at the end of a muscle and attaches into a specific place on the bone. Tendons allow the bony joints to bend, rotate or extend. Tendons are made of the same type of tissue as ligaments; however, ligaments attach two bones to one another.

Physiology

Tendons are made of water, collagen and tenocytes, a specific type of cell found in the tissue of tendons. Tenocytes are a type of cell known as fibroblasts that are responsible for providing maintenance to the collagen. The primary structure of tendons is due to the long, densely-packed fibers of collagen. They are packed in various lengths and, together with proteoglycans, form an extremely strong band of tissue.

Anatomy

Tendons gradually form inside muscle tissue as the muscle tissue ends. Collagen fibers inside the muscle gradually increase and replace the muscle fibers until the entire structure becomes tendon. At the other end of the tendon, the collagen fibers become calcified and gradually integrate into the bone.

Some muscles have a very large tendon, such as the Achilles’ Tendon that is attaching the gastrocnemius muscles of the lower posterior legs. Other muscles, such as the biceps and the triceps muscles, have greater versatility by having more than one tendon attaching the same end of muscle to different bony parts.

Disease states

Tendons can become ruptured from the bony attachment. One of the two biceps muscle tendons and the Achilles’ tendon often suffer from this when the muscle is stronger than the tendon’s ability to keep it held to the bone. Tendonitis is a condition of tendon inflammation that is usually associated with overuse of the muscle and its associated tendon.