THE PNEUMO-GASTBIC NERVE. 



633 



the thorax. 



Its upper 

 ganglion, 



;he spinal accessory, and swells into a ganglion nearly an inch 

 ong (gang, of the trunk). This ganglion lies between the internal 

 jarotid artery and jugular vein, and communicates with several 

 nerves. To reach the thorax, the vagus descends almost vertically courses to 

 jetween the internal jugular vein 

 ind the internal and common 

 carotid arteries ; and it enters that 

 cavity, on the right side, by cross- 

 ing over the subclavian artery, 

 )ut beneath the innominate vein. 



* The ganglion of the root 



jugular ganglion ; fig. 226, 8 ) is of 



greyish colour, and from it small 



tranches in the jugular foramen 



iriae. 



The ganglion of the trunk ( 9 ) is 

 cylindrical in form, reddish in 

 olour, and nearly an inch in 

 ength ; it communicates with the 

 ivpoglossal, spinal, and sympa- 

 thetic nerves. All the intrinsic 

 fibres of the trunk of the nerve 

 enter the ganglion, but those de- 

 ived from the spinal accessory 

 nerve ( 1 i) pass over the ganglion 

 vitliout being connected to it. 



The brandies of the pneumo- 

 jjastric nerve arising in the neck 

 maybe divided into those uniting 

 with other nerves, and those 

 listributed to the several organs. 



Connecting branches (fig. 226) 

 arise from the ganglia of the root 

 md trunk of the vagus. 



FIG. 226. DIAGRAM OF THE NINTH, Branches 

 TENTH, AND ELEVENTH NERVES. 



A. Pons. 



B. Medulla oblongata. 



1. (rlosso pharyngeal nerve. 



2. Vagus. 



3. 3. Spinal accessory. 



4. Jugular ganglion. 



5. Petrosal ganglion. 



6. Tympanic nerve. 



to unite 

 with others ; 



7. Auricular branch. 



8. Root-ganglion, and 9, Trunk- 

 ganglion of vagus. 



10. Branch joining the petrous and 

 upper ganglion of the vagus. 



11. Small part of spinal accessory. 



12. Large part of spinal accessory. 



13. Pharyngeal, and 14, superior 

 laryngeal branch of vagus. 



auricular 

 branch ; 



* From the ganglion of the root. 

 The auricular branch (Arnold's 

 nerve, 7 } is the chief offset, and 

 crosses the jugular fossa to enter 

 an aperture near the root of the 

 styloid process ; it traverses the 

 substance of the temporal bone, 

 and is distributed to the outer 



ear. Its farther course will be described with the anatomy of the ear 

 (page 814). 



* One or two short filaments unite this ganglion with the small with 



f Al _ . , eleventh, 



3art ot the spinal accessory nerve ; and a branch from the upper S ympa- 



gauglion of the sympathetic enters it. Occasionally there s an 

 onset ( 10 ) to join the petrosal ganglion of the glosso-pharyngeal nerve. with 

 From tJie ganglion of the trunk. Communicating filaments pass twelfth, 



