THE PERIPHERylL NERyOUS 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=opliaryngeus; b, N. hypoglossus; <", N. accesjoriits; d, ganglion nodo- 

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

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

 thyrohyoid from ramus descendens of N. hypoglossus; //, 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 scapulrc ventralis; 5? M. longus capitis; 6, trachea; 

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

 strictor pharyngis inferior; 11, 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- 



