118 THE HUMAN BODY. 



white cords which consist nearly entirely of white fibrous*, 

 connective tissue. These terminal cords are called the 

 tendons of the muscle and serve to attach it to parts of the 

 bony or cartilaginous skeleton. In Fig. 48 is shown the 

 biceps muscle of the arm, which lies in front of the humerus. 

 Its fleshy belly, Bb, is seen to divide above and end there 

 in two tendons, one of which, Bl, is fixed to the scapula, 

 while the other joins the tendon of a neighboring muscle 

 (the coraco-bracMal) and is also fixed above to the shoulder- 

 blade. Near the elbow-joint the muscle is continued into 

 a single tendon, B', which is fixed to the radius, but gives- 

 an offshoot, B , to the connective-tissue membranes lying, 

 around the elbow- joint. 



The belly of every muscle possesses the power of shorten- 

 ing forcibly under certain conditions. In so doing it pulls 

 upon the tendons, which being composed of inertensible> 

 white fibrous tissue transmit the movement to the hard 

 parts to which they are attached, just as a pull at one end 

 of rope may be made to act upon distant objects to which 

 the other end is tied. The tendons are merely passive 

 cords and are sometimes very long, as for instance in the 

 case of the muscles of the fingers, the bellies of many of 

 which lie away in the forearm. 



If the tendons at each end of a muscle were fixed to the 

 same bone the muscle would clearly be able to produce no- 

 movement, unless by bending or breaking the bone; the- 

 probable result in such a case would be that the muscle 

 would be torn by its own efforts. In the Body, however, 

 the two ends of a muscle are always attached to two differ- 

 ent pieces of the skeleton, between which more or less 

 movement is permitted, and so when the muscle pulls it 

 alters the relative positions of the parts to which its ten- 

 dons are fixed. In the great majority of cases a true joint 

 lies between the bones on which the muscle can pull, and 

 when the latter contracts it "produces movement at the 

 joint. Many muscles even pass over two joints and can 

 produce movement at either, as the biceps of the arm 

 which, fixed at one end to the scapula and at the other to 

 the radius, can move the bones at either the shoulder or 



