DIGESTION IN THE MOUTH 745 



The intimate dependence of the secretion of saliva on the events 

 occurring in the mouth shows that the activity of the salivary glands 

 must be excited by reflex means. The afferent nerves in this reflex 

 are those that supply the mucous membrane of the mouth, i.e. the 



FIG. 321. Diagram of nerve-supply to sub -maxillary gland. 

 Sm.G, sub-maxillary gland ; N.L, lingual nerve ; Ch.T, chorda tympani ; 

 Sm.Gl, sub-maxillary ganglion ; Sm.D, Wharton's duct ; V. J, jugular vein ; 

 C.A, carotid artery ; G.C.S, superior cervical ganglion ; N.S, sympathetic fibres 

 ramifying on facial artery. (After FOSTER.) 



fifth nerve and the glossopharyngeal. The efferent channels of the 

 reflex were discovered by Ludwig. Each one of the large salivary 

 glands receives nerve fibres from two sources, viz. from the cerebro- 

 spinal and from the sympathetic system. It is probable that 



Mylohyoid 



Lingual. N 



bmx. 



Hyogflossus 



Geniohyoid 



FIG. 322. Diagram of the arrangement of the nerve-supply to the sub- 

 maxillary gland, as exposed in an actual experiment. 

 Duct.Wh, Wharton's duct (of sub-maxillary) ; Duct.E.L, retro-lingual 

 duct; Ch.Ty, chorda tympani nerves. (ALCOCK and ELLISON.) 



the cerebrospinal supply is derived always from one part of 

 the cerebral axis, namely, from the filaments which make up the 

 nervus intermedius. From this point they diverge in their course 

 to the glands. The fibres to the sub-maxillary, the sub-lingual, 

 and the retro- lingual glands pass into the facial nerve, and then 



