30 



DISSECTION OF THE UPPER LIMB. 



Dissection, 



nerves 

 of sub- 

 scapularit 



Subscapu- 

 laris : 



origin 



insertion 



relations ; 



cover 



of the coracoid process at its upper and inner part is also seen 

 (fig. 11, F). 



Dissection. By the separation of the serratus from the sub- 

 scapularis there comes into view a thin fascia, which belongs to the 

 latter muscle, and is fixed to the bone round its margins ; after it 

 has been observed, it may be taken away. 



In cleaning the muscle, the short, uppermost, subscapular branch, 

 of the posterior cord of the brachial plexus will be found entering 



its upper part under 

 of the axillary 

 and a branch 

 from the lowest sub- 

 scapular nerve will be 

 seen to enter its lower, 

 or axillary, border. 



The subscapularis 

 muscle is to be followed 

 forwards to its inser- 

 tion into the humerus ; 

 and the axillary vessels 

 and nerves, with their 

 offsets to the muscles, 

 should be well cleaned. 

 The SUBSCAPULARIS 

 MUSCLE (fig 11, A) lies 

 beneath the scapula, 

 and is for the most 

 part concealed by that 

 bone when the limb is 

 in its natural position. 

 It arises from the con- 

 cave ventral surface of 

 the scapula, except 

 near the upper and 

 lower angles, and over 

 the neck ; and a thick 

 portion of the muscle 

 is attached in the 

 groove along the axillary margin of the bone : many of the fleshy 

 fibres spring from tendinous septa which are fixed to the ridges on 

 the surface of the scapula (fig. 10). The muscle is inserted by a tendon 

 into the impression on the small tuberosity of the humerus, and by 

 fleshy fibres into the bone for nearly an inch below this part (fig. 17). 

 By one surface the muscle forms a part of the posterior wall of 

 the axilla, and is in contact with the axillary vessels and nerves, 

 and the serratus magnus. By the other it rests against the scapula 

 and the shoulder-joint ; and between its tendon and the root of the 

 coracoid process is a bursa, which generally communicates with the 

 synovial cavity of that joint. 



The lower border of the muscle projects beyond the scapula, and 



FIG. 



11. VIEW OF THE SUBSCAPULARIS 

 THE SURROUNDING MUSCLES. 



A. Subscapularis. 



B. Teres major. 



c. Latissimus dorsi. 



r>. Serratus magnus. 



E. Omohyoid. 



p. Pectoralis minor. 



G. Biceps. 



H. Coraco-brachialis. 



a. Suprascapular 

 artery. 



1. Suprascapular 

 nerve, separated from 

 the artery by the supra- 

 scapular ligament. 



