THE VAGUS NERVE. 



1269 



Leaving the canal the nerve supplies 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 off from the upper portion of the gang- 



FIG. 1079. 



Lower head of external pterygoid muscle 

 Internal pterygoid muscl 



Auriculo-temporal nerve 

 Internal carotid artery 



Pneumogastric nerve 

 Inferior dental nerve 

 Spinal accessory nerve - 

 Part of facial nei 

 Hypoglossal nerve 

 Stylo-pharyngeus muscle 

 Glosso-pharyngeal nerve 



I. cervical nerv 



Pneumogastric nerve 



Superior cervical ganglion of 



sympathetic 



Superior laryngeal nerve 

 Descendens hypoglossi 

 1 1. cervical nerve 

 III. cervical ner 



IV. cervical nerve T 



Association cord of 

 sympathetic 



Middle cervical ganglion^ 



Inferior cervical 

 gang! 



Phrenic nerve 



Branches from inf. 

 cervical ganglion 



Inferior cervical cardia 

 of sympathet: 



Recurrent laryngeal 



nerve 

 Internal mammary artery 



Cartilage of I. rib' 



Clavicular facet of sternu 



Lingual nerve 

 External laryngeal branch 



uperior 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 



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 plexiis (plexus pharyngeus) (Fig. 1078). This plexus contains one or 



