THE NERVES. 397 



(of dura mater) behind nerv. glosso-pharyng.; before v. jugular, 

 interna ; it forms a ganglion to which nerv. accessor. Willisii is 

 applied. Below the foram. jugulare it forms a plexus ganglia- 

 form.; is placed at first before, then on the inner side ofven.jugu- 

 laris, n. accessor, and hypoglossus ; it passes downwards along the 

 neck behind carotis (within) andjugularis (without), in one sheath 

 with them, separated from n. sympathicus (which is behind and 

 outside) by uniting tissue, to the thorax, and from this with the 

 oesophagus through the diaphragm, where it terminates in the 

 plexus Solaris on the stomach. 



643. (I.) The cranial portion. 



a. Ganglion, jugulare n. vagi, lies, almost enclosed in dura 

 mater, in the superior part of the for. jugulare, oval, flat, and 

 two lines long, receives a few filaments from n. accessorius, 

 glosso-pharyng., sympathicus and facialis. From its ante- 

 rior external side arises : 



1. N. auricularis. The auricular branch passes round the 

 bulbus v. jugul. forwards, gives a filament to n. Jacobsonii, 

 passes through a canal behind proc. styloideus into the 

 canal. FaUopice, here anastomoses with n. facialis, passes 

 through a canal in the proc. mastoid. again outwards to 

 the skin of the posterior part of the external auditory 

 meatus. (Important on account of the sympathy existing 

 between the Ear, Lungs, and Stomach. ARNOLD.) 



2. Connecting twigs with the gangl. cervicale I. (See this.) 



644. (II.) The cervical portion. 



b. Plexus ganglioformis s. nodosus, lies half an inch below the 

 foram. jugulare, and is a loose plexus of the fasciculi of the 



vagus, the meshes of which are filled with a grayish-red fat. 

 It unites with nerv. hypoglossus, glosso-pharyng. and sympa- 

 thicus, sometimes also with the first cervical nerves. From 

 it arise : 



1 . Nn. pharyngei. The superior pharyngeal nerve unites 

 with n. hypoglossus, passes to m. constrictor super., and 

 the mucous membrane. The delicate middle unites with 

 n. pharyngeus, the glosso-pharyng., and passes with these 

 also to the superior part of the pharynx. The inferior 

 descend obliquely, unite with n. sympathicus, and termi- 

 nate in m. constrictor medius and crico-pharyngeus. 

 They form : 



