THE THORAX 



965 



p.f?,'? 



AJ^ 



Behind the root of the right lung the nerve becomes flattened out 

 and breaks up into numerous branches, which are disposed in a 

 plexiform manner, and constitute the right posterior pulmonary 

 plexus, from which branches are given off to the right lung. From 

 the lower part of this plexus the nerve issues in the form of two 

 cords, which descend in the posterior mediastinum upon the right 

 side of the oesophagus, or gullet, and communicate freely with the 

 corresponding cords of the left side. In this manner a plexus 

 is formed, which is called the plexus gulce. Subsequently the two 



cords of the right side unite 

 to form a single ner\^e, which 

 descends on the posterior surface 

 of the oesophagus, and enters 

 the abdomen through the oeso- 

 phageal openingof the diaphragm 

 to be distributed to the posterior 

 surface of the stomach. 



The left pneumcgastric, or 

 vagus, nerve enters the thoracic 

 cavity between the left common 

 carotid and left subclavian 

 arteries, and descends in the 

 superior mediastinmn behind the 

 left innominate vein. It then 

 passes in front of the arch of the 

 aorta, having the left phrenic 

 nerve on its right side and an- 

 terior to it, with the intervention 

 of the superior cervical cardiac 

 branch of the left sympathetic 

 and its own inferior cervical 

 cardiac branch. At the lower 

 border of the arch it gives off 

 its inferior or recurrent laryn- 

 geal branch, and then passes 

 to the posterior aspect of the 

 root of the left lung. Behind 

 the root of the left lung the 

 nerve, as on the right side, 

 becomes flattened out and 

 breaks up into numerous 

 branches, which are disposed in a plexiform manner, and constitute 

 the left posterior pulmonary plexus, from which branches are given 

 off to the left lung. Frori the lower part of this plexus the nerve, 

 as on the right side, issues in the form of two cords, which descend 

 m the posterior mediastinum upon the left side of the oesophagus 

 or gullet, and communicate freely with the corresponding cords 

 of the right side. In this manner, as stated, a plexus is formed, which 

 IS called the plexus gulce. Subsequently the two cords of the left 

 side unite to form a single nerve, which descends on the anterior 



)7i!i. 395. — Scheme of Pneumogas- 

 TRic Nerve in Thorax and 

 Abdomen (Flower). 



C.P. Branches to Cardiac Plexus 

 P. P.P. Branches to Posterior Pul- 

 monary Plexus 

 A. P. P. Branches to Anterior Pul- 



monarj' Plexus 

 T.S.G. Branches from Upper Thoracic 

 Ganglia of Sympathetic 

 P.O. Plexus fiute 

 G. B. Gastric Branches 



