362 



A MANUAL OF PHYSIOLOGY 



Y21 



The Influence of the Nervous System on the Digestive 

 Glands. 



(i) The Influence of Nerves on the Salivary Glands. All 



the salivary glands have a double nerve-supply, from the 

 medulla oblongata through some of the cranial nerves, and 



from the spinal cord 

 through the cervical 

 sympathetic (Fig. 

 - 143)- 



In the dog the 

 chorda tympani 

 branch of the facial 

 nerve carries the 

 cranial supply of the 

 sublingual and sub- 

 maxillary glands. It 

 joins the lingual 

 branch of the fifth 

 nerve, runs in com- 

 pany with it for a 

 little way, and then, 

 breaking off, after 

 giving some fibres to 

 the lingual, passes, as 

 the chorda tympani 

 proper, along Whar- 

 ton's duct to the sub- 

 maxillary gland. In 

 the hilus of this gland 

 most of its fibres break 

 up into fibrils around 

 nerve - cells situated 

 there and lose their 



FIG. 143. NERVES OF THE SALIVARY GLANDS. 



SM and SL, submaxillary and sublingual glands 

 P, parotid ; V, fifth nerve ; VII, facial ; GP, glosso 



pharyngeal ; L, lingual ; CT, chorda tympani ; CL, medulla in doing SO. 



chordo-lingual ; D, submaxillary ( Wharton's) duct ; A few fibres terminate 



C, ganglion cell of so-called submaxillary ganglion in a similar manner 



in the chordo-lingual triangle, connected with a before entering the 



nerve fibre going to sublingual gland; C", ganglion hilus, and a few 



cell in hilus of submaxillary gland ; SSP, small deeper in the gland. 



superficial petrosal branch of the facial ; OG, otic TV. A 



1 T-RjT f 'ii i- - f r- f 1 X 11C lltH VLJllo LlCtLll IS 



ganglion; IM, inferior maxillary division of fifth rrm miw i 

 nerve ; AT, auriculo-temporal branch of fifth ; JN, ( 

 Jacobson's nerve; C', ganglion cells in superior 

 cervical ganglion (SG) connected with sympathetic 

 fibres going to parotid, submaxillary and sublingual nerve - cells, which, 

 glands. The figure is schematic. passing in as non- 



medullated fibres, 



end in a plexus on the basement membrane of the alveoli. From 

 the plexus fibrils run in among the gland-cells, but do not seem 

 to penetrate them. The lingual, the chorda tympani proper, and 

 Wharton's duct form the sides of what is called the chordo- 

 lingual triangle. Within this triangle are situated many ganglion 

 cells, a special accumulation of which has received the name of the 

 submaxillary ganglion. This, however, should rather be called the 



ii r der process* 

 I 1. Ot tnese 



