AXILLARY SPACE 



45 



N. Thoracodorsalis (O.T. Long Subscapular Nerve). The 

 thoraco-dorsal nerve springs from the posterior cord of the 

 plexus, passes obliquely downwards and laterally, through the 

 axilla, and joins the thoraco-dorsal artery near the lower part 

 of the lateral border of the subscapularis muscle. After cross- 



Scalenus medius 

 Scalenus anterior 



Upper part of Serratus 

 anterior 



Middle portion of 

 Serratus anterior 



Lower portion 

 of Serratus 



FIG. 23. Serratus Anterior muscle and origin of the External Oblique 

 muscle ; the scapula is drawn away from the side of the chest. 



ing in front of the artery it terminates in the latissimus dorsi, 

 which it supplies. 



N. Thoracalis Longus (O.T. Posterior Thoracic or Ex- 

 ternal Respiratory Nerve of Bell). The long thoracic 

 nerve may now be studied in its whole length. It passes 

 downwards on the lateral surface of the serratus anterior, and 

 is the nerve of supply to that muscle. It arises, in the root of 



