436 OTIC GANGLION. 



ganglion, through the pterygoid or Vidian canal, to the foramen jacerum 

 basis cranii, where it divides into two branches, the carotid and petrosal. 

 The carotid branch (n. petrosus profundus) crosses the foramen lacerum, 

 surrounded by the ligamentous substance which closes that opening and 

 enters the carotid canal by several filaments to join the carotid plexus. 

 The petrosal branch (n. petrosus superficialis major) enters the cranium 

 through the foramen lacerum basis cranii, piercing the ligamentous sub- 

 stance of the latter, and passes backwards beneath the Casserian ganglion 

 and dura mater, embedded in a groove upon the anterior surface of the 

 petrous bone, to the hiatus Fallopii. In the hiatus Fallopii the- petrosal 

 branch of the Vidian receives a twig from Jacobson's nerve, and termi- 

 nates in the intumescentia gangliformis of the facial nerve. 



While in the pterygoid canal the Vidian nerve sends off a minute 

 branch which passes through an opening in the sphenoid bone and joins 

 the otic ganglion. 



The OTIC GANGLION (Arnold's)* is a small oval-shaped and flattened 

 ganglion, resting against the inner surface of the inferior maxillary nerve, 

 immediately below the foramen ovale ; it is in relation externally with the 

 trunk of the inferior maxillary nerve, just at the point of union of the motor 

 root ; internally it rests against the cartilage of the Eustachian tube and 

 tensor palati muscle ; and posteriorly it is in contact with the arteria me- 

 ningea media. It is closely adherent to the internal pterygoid nerve, and 

 appears like a swelling upon that branch. 



The branches of the otic ganglion are seven in number ; two of distri- 

 bution, and five of communication. 



The branches of distribution are, a small filament to the tensor tympani 

 muscle, and one to the tensor palati muscle ; the latter is usually derived 

 from the internal pterygoid nerve, at the point where that nerve is enclosed 

 by the ganglion. 



The branches of communication are, two or three filaments to the outer 

 portion of the inferior maxillary nerve ; one or two filaments to the auri- 

 cular nerve ; a filament to the chorda tympani ; filaments to the arteria 

 meningea media to communicate with the nervi molles ; a filament which 

 enters the cranium through the foramen spinosum with the arteria me- 

 ningea media, and accompanies the nervus petrosus superficialis minor to 

 the hiatus Falopii, where it joins the intumescentia gangliformis of the 

 facial nerve ; a filament which enters the cranium through a small canal 

 behind the foramen xotundum to join the Casserian ganglion ; a fil? aaent 

 which enters a small canal near the foramen ovale to communicate with 

 the Vidian nerve ; and the nervus petrosus superficialis minor. The latter 

 nerve ascends from the ganglion to a small canal situated between the 

 foramen ovale and foramen spinosum, and passes backwards on the 

 petrous bone to the hiatus Falopii, where it divides into two filaments. 

 One of these filaments enters the hiatus and joins the intumescentia gan- 

 gliformis of the facial ; the other passes to a minute foramen nearer the 

 base of the petrous bone and enters the tympanum, where it communicates 

 with a brunch of Jacobson's nerve. 



The SUBMAXILLARY GANGLION is a small round or triangular ganglion, 



* Frederick Arnold, "Dissertatio Inauguralis de Parte Cephalica Nervi Sympathetic!," 

 Heidelberg, 1826; and "TJeber den Ohrknoten," 1828 



