THORACIC GANGLIA. 169 



flattened, reposing between the optic nerve and the external rectus 

 muscle.* It communicates with a branch of the nasal nerve,^ and 

 a branch of the third, called ciliary ;* a small filament^ passes from 

 this ganglion to join the carotid plexus. The sj^heno-palatine gan- 

 glion is called also Meckel's ganglion.^ From this are given off the 

 vidian nerve,^* the deep petrous branch of which joins the carotid 

 plexus, as has been mentioned, and the superficial petrous,*^ which 

 enters the hiatus Fallopii, and emerging at the glenoid fissure as the 

 chorda tympani,*** descends in connexion with the gustatory nerve*^ 

 to join the submaxillary ganglion. 



The ganglion of Meckel communicates with the superior maxil- 

 lary nerve by means of its two ascending branches, called pterygo- 

 palatine ; one of its spheno-palatine branches,^^ called naso-palatine,*^ 

 joins its fellow in the foramen incisivum, to form the ganglion of 

 Cloquet, or naso-palatine ganglion. Its descending branches" sup- 

 ply the palate, gums, and fauces. 



The otic ganglion, is a small oval ganglion adhering to the inner 

 surface of the inferior maxillary nerve, below the foramen ovale ; 

 it sends branches of communication to the superior and inferior max- 

 illary, to the vidian and tympanic nerves, and it also supplies the 

 tensor tympani and the tensor palati muscles. 



CERVICAL GANGLIA. 



These are three in number. The first^ is a long, gray, spindle- 

 shaped ganglion extending to the lower border of the third cervical 

 vertebra, behind the sheath of the vessels of the neck. Its branches 

 are numerous, and some are very soft, hence termed nervi molles. 

 They communicate with the anterior trunks* of the first, second, 

 and third cervical nerves ; by an ascending branch^ with the carotid 

 plexus, and by a descending branch^ with the second cervical gan- 

 glion. Its internal branches^ join the facial, eighth, and ninth nerves, 

 and the pharyngeal plexus. A number of branches join to form the 

 superior cardiac nerve,^ which descends behind the vessels and joins 

 the cardiac ganglion. 



The middle cervical ganglion is usually small and sometimes 

 wanting. It rests upon the inferior thyroid artery in front of the 

 fifth or sixth cervical vertebra. It is often called the thyroid gan- 

 glion. Its branches join the superior and inferior cervical ganglia, 

 and the anterior trunks of the third, fourth, and fifth cervical nerves ; 

 it also sends the middle cardiac nerve'' to join the cardiac plexus. 



The inferior cervical ganglion is larger than the last, and is 

 situated in front of the root of the transverse process of the seventh 

 cervical vertebra. Its filaments join the sixth, seventh, and eighth 

 cervical nerves, and also form the inferior cardiac nerve, which joins 

 the middle cardiac nerve and the cardiac plexus. 



The cardiac ganglion is situated beneath the arch of the aorta. 



15 



