416 



PRACTICAL ANATOMY. 



glands with secretory and vasodilator fibres, and the anterior part of the tongue 

 with taste fibres. The facial supplies the stylo-hyoid, the posterior belly of the 

 digastric, all the dermal muscles about the ear, the posterior belly of the occipito- 

 frontalis, and all the muscles of facial expression. (7) The facial nerve commu- 

 nicates with the three divisions of the fifth on the face ; with the spheno-palatine, 

 otic, and submaxillary ganglia ; with the auditory, vagus, sympathetic, and glosso- 

 pharyngeal nerves. 



Describe briefly the auditory ncri'c. 



This is the eighth cranial nerve. It leaves the cranium by the internal auditory 

 meatus with the auditory artery a branch of the basilar and the seventh or facial 



: MAXILLARY rxi--i-:i:ini: MAXILLAHY 



GAS8EB.IAX 



GAXGLIH\ 



SMALL SUPER- 

 FICIAL PETROSAL 



LARGE SUPER _ 



FICIA L PETROKA L * f, / 



e> 



TUBARIU8 



FEffESTRA OVA LI X AXD 

 ROTUXDA IX THE IXXE1! 

 WA LI. 



FACIAL XERVE 



POSTERIOR WALL 



FIG. 292. Box ILLUSTRATION OF SEVENTH CRANIAL NERVE IN RELATION TO THE MIDDLE 



EAR OR TYMPANUM. 



For purposes of aiding Ihe memory, the tympanum is compared to a box. The reader is referred to 

 page 135 for a full description of the figure. 



nerve. In the auditory canal it communicates with the seventh nerve by the pars 

 intermedia. The eighth is the nerve of the special sense of hearing. (For the 

 distribution of this nerve see Morris.) 



Describe the glosso-pharyngeal nerve. 



This is the ninth cranial nerve. It escapes from the cranium by the jugular 

 foramen with the tenth and eleventh nerves and the jugular vein. The nerve 

 has two ganglia: (i) The jugular and (2) the petrosal ganglion. The ninth 

 nerve distributes branches to the mucous membrane of the tongue, pharynx, 

 tympanum, and also to the stylo-pharyngeus muscle. It supplies the otic gang- 

 lion via its communications with the small superficial petrosal branch of the 



