MUSCLES OF THE ARM. 



713 



of the latissimus dorsi and teres major behind, and the pec- 

 toralis major in front. Becoming fleshy it unites with the 

 belly of the short head, at first loosely by cellular tissue, but 

 a little below the middle of the arm the two heads become 

 inseparably united to form a thick fleshy belly, which a 

 little above the elbow-joint ends in a flat tendon, passing 

 in front of the joint to be inserted into the posterior part 

 of the tubercle of the radius. 



A bursa is placed between the tendon and the tubercle, 

 and from the ulnar side of the tendon proceeds the bicipital 

 aponeurosis, which, passing over the brachial artery and 

 nerve, joins the general fascia of the forearm. 



Function. To flex the forearm. This muscle is related 

 with the brachial artery, which see. 



Coraco-brachialis , (Fig. 225.) Arises from the coracoid 

 process, in common with the short head of the biceps, ten- 

 dinous and fleshy. It descends, connected with the short 

 head about three or four inches, along the inner arm to be 

 inserted tendinous and fleshy into the inner side of the 

 humerus, about its centre, and by an aponeurosis into the 

 ridge leading to the internal condyle. 



Function. To raise the arm and draw it forward ; it can 

 also turn it outward. The musculo-cutaneous nerve pene- 

 trates this muscle. It is related with the brachial artery, 

 which see. 



The brachialis anticus or internus (Fig. 225) arises on 

 either side of the insertion of the deltoid by two fleshy 

 slips, which uniting descend, occupying the whole front of 

 the lower part of the humerus, to be inserted into the coro- 

 noid process of the ulna by a strong tendon. This tendon 

 is between the supinator radii longus and pronator radii 

 teres, and passes beneath the tendon of the biceps and over 

 the elbow-joint. 



Function. To bend the forearm and strengthen the 

 elbow-joint. This muscle also, as the biceps, has a relation 

 with the brachial artery, which see. 



Triceps extensor cubiti *?"* *$o3uu$, three heads (Fig 

 226.) This is a three-headed muscle, large and powerful, 



