252 HUMAN PHYSIOLOGY 



fibres which reach the sphenopalatinum ganglion through 

 the petrosus superficialis major; thence they proceed to the 

 levator palati mollis and azygos uvulae. Besides these the 

 facial contains secretory and vaso-dilator fibres which, in the 

 chorda tympani, join the lingualis and with this proceed to 

 the salivary glands. 



VIII. The auditory contains, in the nervus cochlearis, 

 the nerves of hearing. It also contains, in the nervus ves- 

 tibularis, fibres which proceed from the semicircular canal 

 of the internal ear, the organ of the sense of equilibrium, to 

 the brain. These fibres reflexly influence the coordinated 

 movements of the body for maintaining its position and 

 equilibrium. 



IX. The glossopharyngeal contains: 



1. Sensory fibres for the posterior parts of the tongue, 

 pillars of the fauces, tonsils, jaw, and epiglottis. 



2. Motor fibres for the stylopharyngeal muscles and the 

 median pharyngeal constrictor. 



3. Nerves of taste. The nerves supplying the posterior 

 part of the tongue proceed thither directly. Those supply- 

 ing the anterior part pass from the petrosus ganglion of the 

 glossopharyngeal through the tympanic plexus to the genic- 

 ulate ganglion of the facial, thence they proceed through 

 the chorda tympani to the lingual. It is supposed that some 

 of the taste nerves of the glossopharyngeal pass through the 

 tympanic plexus and the Jacobson's anastomoses to the 

 nervus petrosus superficialis minor, otic ganglion, lingual, 

 etc. 



4. Secretory fibres which pass through the Jacobson's 

 nerve and the nervus petrosus superficialis minor, etc., to 

 the parotid glands. 



X. Vagus and XI. spinal accessory form together a 

 mixed nerve whose centrifugal fibres originate from the 

 accessory, and the centripetal from the vagus. The external 

 branch of the accessory contains motor fibres for the sterno- 

 cleido-mastoid and the cucullaris muscle. The common 

 vago-accessory send fibres 



