336 HUMAN ANATOMY. 



3. Internal, 5 Superior nasal, 



I Naso-palatme; 



{Vidian, 

 Large superficial petrosal, 

 Deep petrosal, 

 Pharyngeal branch. 



The Vidian nerve passes from the back part of Meckel's 

 ganglion through the foramen lacerum medium,, where it divides 

 into the large superficial and deep petrosal nerves. It gives 

 off the upper posterior nasal branches to the mucous membrane 

 of septum, orifice of Eustachian tube, and roof of the nose. Or, 

 more correctly, the Vidian is formed by the union of the great 

 petrosal (large superficial petrosal) from the facial and the large 

 deep petrosal from the carotid sympathetic, runs forward through 

 the Vidian canal, and joins the spheno-palatine ganglion (Meek- 

 el's). In this description, the nerves given off to the nasal 

 mucous membrane must be considered branches from the gan- 

 glion inclosed in the same sheath. 



The large superficial petrosal branch enters the cranium 

 through the foramen lacerum medium, passes beneath the dura 

 mater and Gasserian ganglion, enters the hiatus Fallopii, re- 

 ceives a branch from the tympanic branch of the glosso-pharyn- 

 geal (Jacobson's), and through the aquaeductus Fallopii to termi- 

 nate in the geniculate ganglion of the facial nerve. 



The large deep petrosal branch crosses the foramen lacerum 

 medium to the carotid canal, where it joins the carotid plexus 

 of the sympathetic. 



The pharyngeal or ptery go- palatine nerve desends from the 

 back part of the ganglion through the pterygo-palatine canal, 

 to supply the upper part of the pharynx. 



Besides the Vidian and its branches there are two other 

 petrosal nerves (vide Facial Nerve), the small and external 

 petrosal. 



The small petrosal connects the geniculate ganglion of the 

 facial, within the aquseductus Fallopii, with the otic ganglion. 



The external petrosal connects the geniculate ganglion of 

 the facial, within the same canal, with the sympathetic plexus 

 of the middle meningeal plexus. 



The otic ganglion (Arnold's) is placed below the foramen 

 ovale upon the inferior maxillary nerve, or third division of the 

 fifth. 



Its sensory root is derived from the auriculo-temporal branch 

 of the inferior maxillary; the motor root, from the internal 

 ptery goid branch of the same, the sympathetic root, from the 

 plexus on the middle meningeal artery. Branches are distributed 

 to the tensor palati and tensor tympani muscles. 



