THE PERIPHERAL NERVOUS SYSTEM. 



379 



the sympathetic. (In rare cases the two are distinctly sepa- 

 rated throughout their length.) 



FIG. 156. GLOSSOPHARYNGEAL, HYPOGLOSSAL, VAGUS, SYMPATHETIC, AND 

 FIRST CERVICAL NERVES IN THE NECK. 



a, N. glos=opharyngeus; b, N. hypoglossus; c, N. accessorius ; d, ganglion nodo- 

 sum of vagus nerve; </', N. vagus; e, ganglion cervicale superius of sympathetic; 

 /, ramus descendens of N. hypoglossus (united with first cervical); g, branch to M. 

 thyrohyoid from ramus descendens of N. hypoglossus; A, N. laryngeus superior of 

 N. vagus; i, united vagus and sympathetic nerves ; _/, first cervical nerve; k, second 

 cervical nerve; /, N. pharyngeus from vagus, i, M. masseter; 2, outline of external 

 ear; 3, M. splenius; 4, M. levator scapulae ventralis; 5. M. longus capitis; 6. trachea; 

 7, M. sternothyreoideus ; 8, M. sternohyoideus; 9, M. thyreohyoideus ; 10, M. con- 

 strictor pharyngis inferior; n, M. constrictor pharyngis medius; 12, cut end of M. 

 stylohyoideus ; 13, M. hyoglossus; 14, M. stylopharyngeus; 15, bulla tympani; 16. 

 M. jugulohyoideus ; 17, M. styloglossus ; 18, M. mylohyoideus. 



Branches of the vagus in the cervical region (Fig. 156). 



a. N. auricularis. This leaves the ganglion jugulare, 

 passes into the petrous bone to the facial canal, leaves the skull 

 with the facial nerve by the stylomastoid foramen, and is dis- 

 tributed to the external ear. 



b. N. pharyngeus (/). This leaves the vagus craniad of 

 the ganglion nodosum, passes ventrad, sends a small com- 

 municating branch to N. laryngeus superior (//), and is dis- 



