NERVE MECHANISM OF SALIVARY SECRETION. 



141 



gland cells. This question, therefore, will be treated somewhat 

 in detail. 



There are two sets of nerves going to the salivary glands, one 

 belonging to the sympathetic and the other to the cerebro-spinal 

 systems, both of which have been proved to exert a certain 

 amount of influence on the action of the glands, the share taken 

 by each apparently differing in different animals. 



The sympathetic branches for the sub-maxillary and sublingual 



FIG. 64. 



Diagram of Nerves of the Sub-maxillary Gland. The dark lines show the course of the 

 nerves going to the gland. (vii) Portio dura; (v) Inferior maxillary division of the 

 fifth cranial nerve; (G) Sub-maxillary ganglion; (s) Sympathetic, round, facial artery 

 (A) ; (s. c. Q.) Superior cervical ganglion. 



gland come from the plexus which embraces the facial artery, 

 those for the parotid come from the plexus surrounding the 

 internal maxillary as that artery traverses the gland. Both of 

 these nervous plexuses are derived from the superior cervical 

 part of the sympathetic nerve. 



The cerebro-spinal fibres for the sub-maxillary and sublingual 

 glands lie in the complex nerve known as the chorda tympani, 

 which comes from the portio dura of the seventh, and joins the 



