Tendon
Tendon, in anatomy, extremely strong cord that is flexible but does not stretch, made of large bundles of white, fibrous protein known as collagen. A tendon joins a muscle with a bone or another muscle. A tendon delivers the pulling force of a muscle to a bone, which makes body motion possible. A tendon attached to a bone is cylindrical while one connected to a flat muscle on the wall of the abdomen is a wide sheet of fibers. The tendons in the hands, wrists, and feet are enclosed in protective membranes and lubricated by a fluid to prevent excessive friction. A larger tendon includes a system of nerves that registers pain when the tendon is squeezed, and triggers a reflex contraction in the adjoining muscle when the tendon is stretched. The Achilles tendon , which extends from midcalf to the heel, is the thickest and strongest tendon in the human body. Rupture of this tendon is a serious injury that most commonly affects athletes participating in events involving sprinting and jumpin...