Till-: NERVES. 





Among the auatomo-physiological facts pertaining to tho study of lit is 



l ion, wo may remark that tlio staphylin. <>r posterior palatine, i 

 derives from it tin* motor property which permits it to excite the con- 

 traction of the muscles in the soft palate. 



3. OTIC (ou ARNOLD'S) GANGLION. It appears to us that the presence 

 of this ganglion is not constant, for wo have sometimes found it replaced 

 by a small plexus provided with some almost mien scupir ganglionifl 

 granulations. 



When it does exist, it presents itself as a small fusiform cnlarg 

 placed within the origin of the inferior maxillary nerve, beneath tin- inser- 

 tion of the Eustachian tube. To discover it, we have only to look for the 

 commencement of the buccal nerve, to which it is joined by some filanu nls 

 which are so short and thick, that we might imagine it to be fixed on that 

 trunk. 



Its sensitive roots are represented by the preceding filaments. The small 

 superficial petrous nerve, coming from the facial, constitutes its mulur rood 

 From the sympathetic ramuscule accompanying the internal maxillary 

 artery, it receives its filament of communication with the superior cervical 

 ganglion. 



Among its emergent ramuscules must be cited a superior filament, which 

 enters the petrous portion of the temporal bone to disappear in the internal 

 muscle of the malleus (tensor tympani), and two inferior filaments of a 

 more considerable volume which separate in numerous ramuscules destined 

 to tho ptorygoid muscles, tho Eustachian tube, and the tensor palati 

 muscle. 



PHYSIOLOGICAL RESUME OF THE FIFTH PAIR. Tho trigemiui convey 

 sensation to the skin covering the head, into the eyelids, the soft and hard 

 palate, the nasal fossa) and sinuses, the nostrils, the greater portion of the 

 tongue, and into the salivary glands and cheeks, and the upper and lower lips. 

 The enormous tuft formed by tho terminal branches of the superior 

 maxillary nervo, endow the upper lip with the attributes of an organ of very 

 exquisite tact. 



The gustatory branch is, for the anterior two-thirds of tho tongue, the 

 essential instrument of the sense of taste. 



By its motor root, the inferior maxillary nerve provokes the contraction 

 of the muscles that bring the jaws into apposition all those composing the 

 masseteric region, except the digastricus. This root is often designated, in 

 consequence of its function, the masticatory nerve. 



The fifth pair also influences, as is demonstrated by vivisections and the 

 observation of pathological facts, the secretion of the mucous membranes 

 and glands receiving its filaments: undoubtedly by a reflex action which 

 proceeds from the isthmus, and perhaps from the Gasserian ganglion. 



Finally, it is admitted that tho nutrition of tho tissues in which the 

 trigeminus ramifies depends upon that nerve. But here there is an exagge- 

 ration ; for if nutrition be modified in these tissues, consequent on tin- 

 section of the fifth pair, this effect is certainly duo to paralysis of the 

 capillaries, whose contractility is probably excited by the organic motor 

 fibres mixed with the sensitive filaments of tho fifth pair. 



The ramuscules sent by tho sympathetic chain to the Gasscrian ganglion, 

 are perhaps not foreign to the part the fifth pair seems to play in the 

 secretory and nutritive functions. 



