THE ANTERIOR LIMB 265 



(b) The deltoideus. Acromial portion. Origin: The acromion. 

 Insertion : Distal portion of the deltoid tuberosity. Scap- 

 ular portion. Origin: Infraspinous fascia. The end of the 

 muscle forms a curved line over the dorsal portion of the 

 infraspinatus, leaving only a small triangular portion of 

 the latter exposed. Insertion: The distal portion of the 

 muscle passes beneath the metacromion, which also 

 serves as a point of attachment, and is replaced on the 

 lateral surface of the humerus, beneath the acromial por- 

 tion, by a thin tendon, through which it is inserted 

 beside the acromial portion. 



* The scapular portion of the deltoideus should be 

 separated from the infraspinatus and divided, the distal 

 end being reflected together with the metacromion. 



(c) The infraspinatus. Origin : Posterior portion of the lateral 

 surface of the scapula, including the spine. Insertion: 

 Greater tubercle of the humerus. The muscle fills the 

 infraspinous fossa. 



(d) The supraspinatus. Origin: Anterior portion of the lateral 

 surface of the scapula (supraspinous fossa), supraspinous 

 fascia, and, to a certain extent, the subscapular fascia. 

 Insertion: Greater tubercle of the humerus. 



The extent of this muscle is evident only after removal 

 of the loosely attached fleshy parts of the pectorals from 

 its surface. 



(e) The subscapularis. Origin: Entire medial surface of the 

 scapula. Insertion: Lesser tubercle of the humerus. 



(/) The teres major. Origin: Dorsal portion of the axillary 

 border of the scapula. Insertion: In common with the 

 latissimus dorsi on the anterior surface of the humerus. 



(g) The teres minor. Origin: Ventral portion of the axillary 

 border of the scapula. Insertion: Greater tubercle. 



The muscle is closely associated with the infraspinatus 

 but is separated from the teres major by the tendon of 

 origin of the long head of the triceps. 



(h) The coracobrachialis. Origin: Coracoid process. In- 



