U6 



THE CEAXIAL NERVES. 



lary near the origin of the nerve for the external pterygoid muscle, and which, 

 from its being occasionally separate from the rett of the inferior dental nerve till 

 after it enters the dental canal, has been called the h'Mcr Inferior denial (Sappolini, 

 " Omodei Annali," 1860). The niylo-hyoid frequently gives off a small branch, 

 which pierces the mylo-hyoid muscle and joins the lingual nerve. This anasto- 

 mosis is said by Sappcy to be constant. 



Otic Ganglion. 



The otic ganglion, or ganglion of Arnold, of a reddish-grey colour, is 

 situated on the deep surface of the lower maxillary trunk, nearly at the 

 point of junction of the motor fasciculus with that nerve, and around 

 the origin of the internal pterygoid branch. Its inner surface is close 

 to the cartilaginous part of tlie Eustachian tube and the circnmflexus 

 palati muscle^ and behind it is the middle meningeal arter}-. 



Conncciion witU tierves — roofs. — The ganglion is connected with the 

 lower maxillary nerve, especially with tlie branch furnished to the in- 

 ternal pterygoid muscle, and with the auriculo-temporal nerve, and thus 

 obtains motor and sensory roots ; it is brought into connection with 

 the sympathetic by a filament from the plexus on the middle meningeal 

 artery. It likewise receives the small superficial petrosal nerve, which 

 emerges from the petrous bone by the small foramen internal to the 

 canal of the tensor tympani muscle, and reaches the exterior of the skull 

 by piercing the sphenoid bone close to the foramen spinosum. By this 

 nerve the ganglion forms a communication with the glosso-pharyngeal 

 and facial nerves. 



Branches. — Two small nerves are distributed to muscles — one to the tensor of 

 the membrane of the tympanum, the other to the circumflexus or tensor palati. 



341. Fig. 341.— Otic Gang- 



lion AND ITS CONNKC- 

 TIOXS FROM THE In- 



siDE (from Sappey 

 after Arnold), g 



This figure exhibits a 

 view of the lateral por- 

 tion of the slvull with a 

 part of the nasal fossa 

 and lower jaw of the 

 right side ; the petrous 

 bone has been removed 

 so as to show the inner 

 surface of the membrana 

 tympani and the canal of 

 the facial nerve. 



1, smaller motor root 

 of tlie fifth nerve passing 

 down on the inside of 

 the Gasserian ganglion to 

 unite with the inferior 

 maxillary division ; 2, 

 inferior dental nerve 

 entering the canal of the 

 lower jaw ; 3, mj'lo-hyoid 

 branch, seen also farther down emerging in front of the internal pterygoid muscle^; 

 4 lingual or gustatory nerve; 5, chorda tympani; 6, facial nerve ni its canal; /, 

 auriculo-temporal nerve, enclosing in its loop of origin the middle meningeal artery; 

 8 otic canglion ; 9, small superficial petrosal nerve joining the ganglion; lU, branch to 

 the tensor tympani muscle ; 11, twig connecting the ganglion with the temporo-auricular 

 nerve • 12 twig to the ganglion from the svmpathetic nerves on the meningeal artery ; 

 13, branch to the internal pterygoid muscle ; 14, branch to the tensor palati muscle. 



