THE VAGUS NERVE. 



1269 



Leaving the canal the nerve supphes the skin of the posterior part of the auricle and 

 of the posterior inferior portion of the external auditory meatus. 



While traversing the temporal bone the auricular nerve communicates with the facial and, 

 after reaching its area of distribution, with the posterior auricular nerve. 



Variations. — The auricular nerve may be absent or may fuse with the main trunk of the 

 facial, its fibres under these circumstances probably reaching their .destination through the pos- 

 terior auricular nerve. Its branch of communication with the facial may be absent. 



3. The pharyngeal branches (rr. pharyngei), usually an upper and a lower 

 but sometimes more or only one, are given of? from the upper portion of the gang- 



FiG. 1079, 



Lower head of external pter\'^oid muscle 

 Internal pterygoid muscle 



Auriculo-temporal nerve, 

 Internal carotid arterv 

 \ 



Pnemnogastric nerve 

 Inferior dental nerve- 

 Spinal accessory nerve 



Part of facial nerve 



Hypoglossal nerve' 



Stylo-pharyngeus muscle 



Glosso-pharyngeal nerve 



I. cervical nerve 



Pneumogastric nerve 



Superior cervical ganglion of 



sympathetic 



Superior laryngeal nerve 



Descendens hypoglossi 

 H. cervical nerve' 



III. cervical nerve 



IV. cervical nerve — rr 



A.ssociation cord of 

 sympathetic 



Middle cervical gangHon,.— 



Inferior cervical 



ganglion 



Phrenic nerve 



Branches from inf. 

 cervical ganglion 



Inferior cervical cardiac 

 of sympathetic 



I-ingual nerve 

 External laryngeal branch 



Superior cervical cardiac of 

 sympathetic 



Middle cervical cardiac of sympathetic 



Recurrent laryngeal nerve 



Middle cervical cardiac of 

 Common . [pneumogastric 



carotid artery 



Inferior cervical cardiac ot 

 pneumogastric 



Recurrent laryngeal 

 nerve 

 Internal mammary arter_. 



Cartilage of I. rib 



Clavicular facet of sternum 



Deep dissection of right side of head and neck, showing lingual, glosso-pharyngeal, pneumogastic hypoglossal 



and sympathetic nerves. 



lion of the trunk and include to a considerable extent fibres brought to the vagus by 

 its accessory portion. They pass downward and inward, between the external and 

 internal carotid arteries, and join the pharyngeal branches from the glosso-pharyn- 

 geal nerve and from the superior cervical ganglion of the sympathetic to form the 

 pharyngeal plexjis (plexus pharyngeus) (Fig. 1078). This plexus contains one or 



