THE SUBMAXILLARY GANGLION 963 



merly described as Cloquet's ganglion) and they furnish twigs to the anterior or premaxillary 

 part of the hard palate behind the incisor teeth. In this situation they communicate with the 

 anterior palatine nerves. 



Descending branches. — The descending branches are the great or anterior, the posterior, 

 and the middle (external) palatine nerves. Like the internal set of branches, they are in part 

 derived from the ganglion and in part are directly continuous with the spheno-palatine nerves 

 (fig. 732). 



The great or anterior palatine nerve, its sensory fibres derived from the maxillary nerve, 

 arises from the inferior angle of Meckel's ganglion, and passes downward through the pterygo- 

 palatine canal, accompanied by the descending palatine artery. Emerging from the canal at 

 the greater (posterior) palatine foramen it divides into two or three branches, which pass for- 

 ward in grooves in the hard palate and supply the glands and mucous membrane of the hard 

 palate and the gums on the inner aspect of the alveolar border of the upper jaw. During its 

 course through the pterygo-palatine canal the anterior palatine nerve gives off the posterior 

 inferior nasal nerves. These nerves pass through small openings in the perpendicular plate 

 of the palate bone to supply the mucous membrane covering the posterior part of the inferior 

 nasal concha (turbinated bone) and the adjacent portions of the middle and inferior meatuses 

 of the nose. 



The posterior or small palatine nerve passes downward through a lesser palatine foramen 

 (accessory palatine canal), and enters the soft palate, distributing branches to that organ, to 

 the uvula, and to the tonsil. Its sensory fibres are derived from the glosso-palatine nerve, 

 through the great superficial petrosal nerve and through the spheno-palatine ganglion. It 

 was formerly believed to convey motor fibres from the facial nerve to the levator palati and 

 azygos uvulae, but it is now believed that these muscles are supplied by the spinal accessory 

 nerve through the pharyngeal plexus (fig. 732). 



The middle (external) palatine nerve, the smallest of the three, in part, likewise from the 

 glosso-palatine nerve, traverses a lesser palatine foramen and supplies twigs to the tonsil and 

 to the adjacent part of the soft palate (fig. 732). 



Posterior branch.— The pharyngeal branch, which is of small size, passes backward and 

 somewhat medialward through the pharyngeal canal accompanied by a pharyngeal branch 

 of the spheno-palatine arterj'. It is distributed to the mucous membrane of the uppermost 

 part of the pharjTix, to the upper part of the posterior nares, to the opening of the Eustachian 

 tube, and to the lining of the sphenoidal sinus. Its sensory fibres are derived from the maxillary 

 nerve. 



The Otic Ganglion 



The otic or Arnold's ganglion is a small reddish-grey body which is associated 

 with the mandibular nerve. It lies deeply in the zygomatic fossa, immediately 

 below the foramen ovale, on the inner side of the trunk of the mandibular nerve. 

 It is in relation internally with the tensor palati, which separates it from the Eusta- 

 chian tube. In front of it is the posterior border of the pterygoideus internus, and 

 behind it lie the middle and small meningeal arteries. It is compressed laterally, 

 and its greatest diameter, which lies antero-posteriorly, is about three millimetres. 



Roots. — The ganglion is closelj' connected with the nerve to the pterj^goideus internus, 

 through which it may receive a motor root from the masticator nerve. Through the small 

 superficial petrosal nerve, which joins the upper and back part of the ganglion, it receives a 

 motor root from the glosso-palatine nerve and sensory and motor fibres from the glosso- 

 pharjTigeal nerve. It receives also a slender sphenoidal filmnent from the Vidian nerve. 

 The sympathetic roots are derived from the small superficial petrosal nerve and from the 

 sympathetic plexus on the middle meningeal artery. 



Branches. — The communicating branches which pass from the ganglion are: — (1) The 

 filaments to the chorda tympani; some of whose fibres probably terminate in the submaxillary 

 ganglion; (2) filaments to the auriculo-temporal nerve; (3) filaments to the spinous nerve 

 (the recurrent branch of the mandibular nerve). The branches of distribution are sympathetic 

 to the vessels and somatic motor branches to the tensor tympani, and tensor veli palatini. 



The Submaxillary Ganglion 



The submaxillar}' ganglion is su.spended from the lingual division of the man- 

 dibular nerve by anterior and posterior branches. It is a small reddish body, of 

 triangular or fusiform shape, which lies between the mylo-hyoideus and hyo- 

 glossus and above the duct of the submaxillary gland. 



Roots. — The sensory root is received from the lingual nerve. The motor root is from both 

 the masticator nerve by way of the lingual nerve, and from the glosso-palatine nerve by way of 

 the chorda tympani. The motor fibres pass from the chorda tympani after it has joined the 

 lingual, and the sensory fibres come directly from the lingual nerve. The sympathetic root is 

 formed by filaments from the sympathetic plexus on the facial artery. 



Branches. — (a) Five or six glandular branches are given to the submaxillary gland and to 

 Wharton's duct. 



(6) Branches to the lingual nerve and the sublingual gland. 



(c) To the mucous membrane of the floor of the mouth. 



