36 MUSCLES OF THE SHOULDER AND ARM. 



c. The most external of the three divisions arises 

 from the head of the humerus just beneath the inser- 

 tion of the teres minor, and from fascia along the outer 

 part of the humerus. 



d. The middle division arises, in common with the 

 last, just beyond the head of the humerus. 



The divisions b, c and d are inserted into the ole- 

 cranon process along with a. 



Cut tliroiigh the bellies of the ti^iceps, and reflect the 

 cut ends. 



19. The Brachialis Anticus is a flat muscle closely 

 adherent to the humerus ; it arises from the dorsal 

 and external aspect of the humerus throughout most 

 of its extent. The fibres pass over to the anterior or 

 ventral face 0/ the humerus, and at the elbow end in a 

 tendon which is inserted into the ulna. The tendon 

 passes between the two terminal tendons of the 

 biceps, fusing with them. 



20. The Sub-anconeus is a very small muscle 

 which arises from the dorsal surface of the distal 

 end of the humerus round the margins of the ole- 

 cranon fossa. The muscle adheres closely to the hu- 

 merus, and is inserted into the olecranon process and 

 outer side of the ulna. 



