THE SUBMAXILLARY GAXGLIOX. 547 



Submaxillary Ganglion. 



The submaxillary or lin,2;ual gangiion is placed above the deep portion 

 of the submaxillary gland, and is connected by filaments with the 

 lingual nerve. It is about the size of the ophthalmic ganglion, and 

 triangular or fusiform m shape. By the upper part or base it receives 

 branches from nerves which may be regarded as its roots, whilst from 

 the lower part proceed the filaments which are distributed from the 

 ganglion. 



Connection ivith nerves — roots. — This ganglion receives filaments from 

 the lingual nerve, and likewise, at its back part, a root which appa- 

 rently comes from the lingual nerve, but is in reality derived from the 

 chorda tympani, which is prolonged downwards in the sheath of the 

 lingual nerve. It receives also small twigs from the sympathetic fila- 

 ment5 on the facial artery. 



Branches. — Some nerves, five or six in number, radiate to the 

 substance of the submaxillary gland. Others from the fore part of 

 the ganglion, longer and larger than the preceding, end in the mucous 

 membrane of the mouth, and in Wharton's duct. 



According to Meckel (" De qumto pare,"' iVc). a brancli occasionally descends in 

 front of the hyo-glossus muscle, and after joining -n-itb. one from the hypoglossal 

 nerve, ends in the genio hyo glossus muscle. 



It may be noticed that wlulo the branches from the otic ganglion pass exclu- 

 sively to muscles, the submaxillary ganghoa gives no muscular offsets. 



Summary. — Cutaneous filaments of the inferior maxillary nerve 

 ramify on the side of the liead, and the external ear, in the auditory 

 passage, the lower lip, and the lower part of the face ; sensory branches 

 are supplied by it to the greater part of the tongue ; and branches are 

 furnished to the mucous membrane of the mouth, the lower teeth and 

 gums, the salivary glands, and die articulation of the lower jaw. 



This nerve supphes the muscles of mastication, viz., the masseter, 

 temporal, and two pterygoid ; also the buccinator, the myio-hyoid, and 

 the anterior belly of the digastric ; and from the otic ganglion proceed 

 the branches to ttie circumflexus palati and tensor tympani muscles. 



SIXTH PAIR OF NERVES. 



Surface Attachment. — The sixth cranial nerve (abducens) motor 

 oculi externus, takes its apparent origin from between the pyramidal 

 body and the pons Varolii by means of a larger and a smaller bundle. 

 It is connected with the pyramid, and to a small extent with the pons 

 also. 



Deep origin. — The fibres pass backwards and a little upwards 

 through the fibres of the pons, parallel with the raphe, to reach a 

 column of large nerve cells situated beneath the eminentia teres. The 

 same nucleus gives origm to a large number of the fibres of the facial 

 nerve, and is termed the common nucleus of the facial and sixth nerves. 



Course and Distribution. — The nerve enters the dura mater behind 

 the dorsum .sellte, and pas.sing forwards in the floor of the cavernous 

 .sinus, close to the outer side of the carotid artery, enters the orbit 

 through the sphenoidal fissure, between the heads of the external 

 rectus muscle, and is entirely distributed to that muscle, piercing it on 

 the ocular surface. In entering the orbit between the heads of thg 



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