THE THORAX 



^59 



I inch below the upper border of the manubrium. It lies in the 

 superior mediastinum, and its left side is in close relation with the 

 left pleura. 



Relations — Anterior. — ^The left phrenic and left pneumogastric 



... Left Common Carotid Arttry 



Scalenus Anticus Muscle 



Left Pneumogastric Nerve 



Left Subclavian Artery 



(Third Part) 

 Left Phrenic Nerve 



Left Superior Intercostal 

 Artery 



Cervical Cardiac Branches 

 of Left Symp. and Vagus 



Superficial Cardiac 

 Plexus 



Left Bronchus 



Fig. 393. — Dissection of the Posterior Wall of the Thorax. 



nerves, the former being on the right side of, and anterior to, the 

 latter. Between these two nerves are the superior cervical cardiac 

 branch of the left sympathetic and the inferior cervical cardiac 

 branch of the left pneumogastric, both on their way to the super- 



