416 ANATOMY IN A NUTSHELL. 



all the intrinsic muscles of the larynx except the Crico-thyroid muscle and 

 communicates with the superior laryngeal. Near the beginning of this nerve 

 it usually gives off a cardiac branch. Between the (esophagus and the trachea 

 it gives branches to these structures and near its termination it gives some 

 branch) s to the Inferior constrictor muscle. On the left side the recurrent laryn- 

 geal nerve conn s in front of the arch of the aorta and winds round the arch ex- 

 ternal to the obliterated ductus arteriosus and passes up the left side of the 

 trachea. The remainder of its course is similar to that of the right side. This 

 nerve passes through the superior opening of the thorax while the right one does 

 not. (6) The cardiac brahches of the pneumogastric all pass to the deep 

 cardiac plexus except the inferior cervical cardiac on the left side. It gives off 

 three cardiac branches, (a) the superior cervical arises from the pneumogastric 

 from the upper part of the neck and join the corresponding branches from the 

 sympathetic, (b) the inferior cervical cardiac nerve of the left side passes down- 

 war* 1 on the 1( f1 side of the arch of the aorta between this arch and the pleura 

 and joins the superficial cardiac plexus. The phrenic nerve is in front of it and 

 the left superior cardiac of the sympathetic is behind it as it crosses the arch of 

 the aorta. On the right side this branch passes in front or beside the innomi- 

 nate artery on the side of the trachea to join the deep cardiac plexus, (c) Tho- 

 racic cardiac branches arise' near the recurrent laryngeal nerve and the one on 

 the right side' is on a higher level than the one em the left because the recurrent 

 laryng< al n< rve com< s off em a higher level on the right side. They pass inward 

 to the fronl of the lower end of the trachea to end in the deep cardiac plexus. 



7 i The anterior pulmonary branches are two or three in number which 

 arise at the upper border at the root of the lung. They join filaments from the 

 sympathetic and form the' anterior pulmonary plexus from which fine branches 

 pass along the branches into the lung. (8) The posterior pulmonary 

 br inches are' larger than the anterior branches anel are joined by filaments from 

 the third and fourth thoracic ganglia of the' sympathetic and form the posterie>r 

 pulmonary plexus from which branche s pass into the- root of the lung. Occasion- 

 ally branches from the first and second thoracic ganglia pass te> this plexus. (9) 

 Oesophageal branches are given off from the- pneumogastric both above and 

 below the pulmonary branches, but the' low* r one s are- larger and more numerous 

 than the' upper ones. These oesophageal branches, with the' corresponding 

 branch* s of the opp< sit< side, form the oesophageal plexus (Gulae plexus). (10) 

 The gastric branches pass through the oesophageal op< ning in the Diaphragm 

 and the 1 < ft one is distributed to the anterior surface of the stomach. Some 

 of the largest branch* - accompany the gastric artery along the lesser curvature 

 of the' stomach, and from these small twigs pass on the' hepatic artery and join 

 the hepatic plexus. The terminal branches of the right pneumogastric are 

 distributed on the posterior surface of the stomach and join the cceliac plexus, 

 splenic plexus, and the 1< ft r< mil plexus. 



LESSON CXVII. 



The eleventh cranial ner\e (Plate CLXXXVII) is called the' spinal acccs- 

 SOry and is purely motor. It consists of two main parts. (1) an ACCESSORY or 

 MEDULLARY PORTION, and (2) \ SPINAL PORTION. THE SUPERFICIAL ORIGIN 



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