248 



THE CRANIAL NERVES. 



the submaxillary ganglion at the place where it is in contact with the submaxillary 

 gland, and a little farther forwards one or two filaments descend over the fore part 

 of the hyo-glossus muscle to join in loops with similar branches of the hypoglossal 

 nerve. 



(b) Branches to the mucous membrane of the mouth are given from the nerve at 

 the side of the tongue, and supply also the gum. Some delicate filaments are like- 

 wise distributed to the sublingual gland. 



(c) The lingual or terminal Ranches perforate the muscular structure of the 

 tongue, and divide into filaments which are directed upwards to the mucous mem- 

 brane of the anterior two-thirds of the organ, where they terminate mainly in the 

 conical and fungiform papillae. Microscopic ganglia are found in their ultimate 

 ramifications. 



Submaxillary Ganglion. 



The submaxillary or lingual ganglion (fig. 181, 7) is placed above the deep 

 portion of the submaxillary gland, and is connected by anterior and posterior fila- 

 ments with the lingual nerve, from which it thus appears to be suspended by a loop. 

 It is somewhat larger than the ciliary ganglion, and triangular or fusiform in 

 shape. The cells of the ganglion are multipolar. Its hinder part receives branches 



Fig. 163. SUBMAXILLARY AND SUBLINGUAL 



GANGLIA OF AN INFANT. (Rauber.) 



from nerves which may be regarded 

 as its roots, while from its fore and 

 lower parts proceed the branches for 

 distribution. 



ROOTS OF THE GAXGLIOX. The 

 pobterior connecting branch from 

 the lingual nerve, often broken up 



into two or three filaments, conveys to the ganglion fibres from the chorda tympani 

 and the inferior maxillary nerve, and thus represents the motor and sensory roots of 

 the ganglion. The sympathetic root is formed by slender twigs from the plexus on 

 the facial artery. 



BRANCHES. Five or six small nerves descend from the ganglion to the sub- 

 maxillary gland, and others run forwards to the mucous membrane of the mouth 

 and Wharton's duct.' The anterior branch of communication with the lingual nerve 

 is probably composed of fibres which pass from the ganglion and are distributed with 

 the offsets of that nerve. There is also occasionally a small branch or two passing 

 to the hypoglossal nerve (Meckel, Bose). 



A minute siiUingual ganglion is described by some anatomists on the filaments passing 

 from the lingual nerve to the sublingual gland (fig. 163 ; 181, 8) ; and small groups of nerve- 

 cells are also found in the adjoining part of the lingual trunk (Rauber;. 



Otic Ganglion. 



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

 shape, flattened from within out, and measures about 4 mm. in its longest (antero- 

 posterior) diameter. It is situated immediately below the foramen ovale, on the 

 deep surface of the inferior maxillary nerve, covering, and not un frequently 

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

 to the cartilaginous part of the Eustachian tube and the tensor palati muscle ; 



