THE MUSCULAR SYSTEM. 



151 



brachialis anticus and short humeral head of the triceps ; action, 

 draws the humerus imvard and forward; nerves, the musculo- 

 cutaneous and a branch of the musculo -spiral. 



BICEPS (FLEXOR CUBITI). Origin, by two heads; short 

 head from the apex of the coracoid process, along with the coraco- 

 brachialis; the long (glenoid) head from the upper margin of 

 the glenoid cavity of the scapula; insertion, into the posterior 



FIG. 97. 



Muscles of shoulder and arm: 4, 

 Bubscapularis; 5, teres major; 6, 

 coraco-brachialis; 7, biceps. 



FIG. 98. 



Triceps muscle: 1, external head; 2, 

 scapular head; 4, insertion. 



part of the tuberosity of the radius ; action, flexes the forearm ; 

 nerve, the musculo-cutaneous. 



BRACHIALIS ANTICUS. Origin, inner and outer surfaces of 

 the shaft of the humerus,, embracing the insertion of the deltoid ; 

 insertion, into the anterior surface of the coronoid process of 

 the ulna; action, flexes the forearm; nerve, the musculo- 

 cutaneous. 



TRICEPS (EXTENSOR CUBITI). Origin, by three heads 

 middle, or scapular head, below the glenoid cavity of the scapula. ; 

 external head, from the posterior aspect of the shaft of the 



