414 ANATOMY IN A NUTSHELL. 



The left pneumogastric nerve passes between the subclavian artery and the 

 carotid artery, behind the left innominate vein. At this point the left phrenic 

 nerve crosses it. It now passes in front of the arch of the aorta behind the root 

 of the left lung where it helps to form the posterior pulmonary plexus. It now 

 passes along the anterior surface of the oesophagus through the Diaphragm to 

 be distributed to the anterior surface of the stomach and the liver. It occasion- 

 ally joins the solar plexus. 



The pneumogastric nerve has the following connections: 



(1) Thk ganglion of the root is joined to the spinal accessory, (2) to the 

 petrous ganglion of the glosso-pharyngeal, (3) to the sympathetic. The gang- 

 lion of thk trunk is joined (1) to the hypoglossal, (2) to the sympathetic, (3) 

 to a loop between the first and second cervical nerves. 



The branches of distribution are (1) meningeal branch (recurrent) which 

 is a small filament given off from the ganglion of the root in the jugular foramen. 

 Ii is distributed to the dura mater in the posterior fossa at the base of the skull. 

 (2) The auricular branch (Arnold's) comes from the ganglion of the root in 

 the jugular foramen. A branch from the petrous ganglion of the glosso-pharyn- 

 geal joins it. The nerve now passes through a foramen in the outer wall of the 

 jugular fossa of the petrous portion of the temporal bone and communicates 

 with the facial nerve. It leaves the temporal bone by the stylo-mastoid fora- 

 men as a rule but it may pass through the tympano-mastoid fissure. Behind 

 the pinna it divides into two branches one of which joins the posterior auricu- 

 lar of the facial, while the other supplies the posterior and inferior part of the 

 externa] auditory meatus and the back of the pinna. (3) Pharyngeal 

 p.i; \ \< ihes are t wo or three and join the pharyngeal branch of the glosso-pharyn- 

 geal on the outer surface of the internal carotid artery and after passing with this 

 artery interna] to the external carotid artery, it turns downward and inward to 

 reach the posterior aspect of the pharynx. At this point the two nerves are 

 joined by branches from the superior cervical ganglion of the sympathetic to 

 help form the pharyngeal plexus. This nerve is the principal motor nerve of the 

 pharynx and comes from the upper part of the ganglion of the trunk of the 

 pneumogastric. .Most of its fibers come from the accessory portion of the 

 spinal accessory nerve. (4) The superior laryngeal nerve comes from the 

 ganglion ^^ the Punk and passes behind the internal carotid artery where it 

 divides into the external laryngeal nerve which branch joins the pharyngeal 

 plexus and the sympathetic, and it supplies the Crico-thyroid muscle and In- 

 ferior constrictor muscle and occasionally the thyroid gland; and the internal 

 laryngeal nerve which passes through the thyro-hyoid membrane to be distri- 

 buted to the mucous membrane of the larynx, and it joins a branch from the 

 recurrenl laryngeal, (5) The inferior oe recurrent laryngeal nerve on 

 the right side arises at the root of the nick in front of the first portion of the 

 right subclavian artery. It passes around the artery and runs upward and 

 and slightly inward behind the common carotid artery. It now runs in a groove 

 between the common carotid artery and the (esophagus, having with it branches 

 of the inferior thyroid artery. It passes under the lower border of the Inferior 

 constrictor of the pharynx into the larynx where it breaks up into branches for 



