Tendon
the white fibrous tissue reaching from the end of a muscle to bone or some other structure which is to serve as a fixed attachment for it, or which it is intended to move. Tendons have been divided into (1) Funicular, or rope-like, as the long tendon of the biceps muscle of the arm. (2) Fascicular, as the short tendon of that muscle and as the great majority of tendons generally. (3) Aponeurotic or tendinous expansions, sometimes of considerable extent, and serviceable in strengthening the walls of cavities, as, for example, the tendons of the abdominal muscles. The tendons commence by separate fascicles from the end of each muscular fiber, and they similarly terminate by separate fascicles in distinct depressions in the bones, besides being closely incorporated with the periosteum. In some birds whose tendons are black the periosteum is black also. If a tendon is ruptured by an accident, or divided by the surgeon (tenotomy), the two ends, if not too far separated, unite with extreme readiness, by the formation of intervening plastic material, which soon acquires great firmness. The tendons most frequently ruptured are the ACHILLES TENDON (q. v.), and tendons of the rectus femoris and the triceps humeri.
Among the diseases of tendons are inflammation and one of the forms of whitlow known as paronychia gravis, or tendinous whitlow. Fibrous tumors and small cartilaginous enlargements are often found in tendons.