132 



MANUAL OF PHYSIOLOGY. 



by the quality of the blood flowing through the special nerve 

 centre itself. 



The channels traversed by the efferent impulses going to the 

 salivary glands have been demonstrated by experiment. In the 

 case of the submaxillary, the route is especially distinct and in- 

 structive, so that from this gland we obtain most of our knowl- 



FIG. 64. 



Diagram of Nerves of the Submaxillary Gland. The dark lines show 

 the course of the nerves going to the gland. (vn.) Portio dura; (v.) Infe- 

 rior maxillary division of the fifth cranial nerve; (o) Submaxillary gan- 

 glion; (s) Sympathetic round facial artery (A); (s. c. o.) Superior cervical 

 ganglion. 



edge concerning the direct influence of nerve impulses on the 

 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. 



