SUBMAXILLARY SALIVA. 



[BOOK ii. 



saliva and gustation, and called attention to the fact that whilst the 

 parotid enters into activity during the mechanical movements of 

 mastication, the submaxillary gland is not affected by them ; whilst 

 on the other hand the stimulation of the sensory nerves of the 

 mouth or, in some cases, the anticipation of food lead to a flow of 

 submaxillary saliva. There can be no question, however, that the 

 parotid likewise is affected reflexly by stimulation of the nerves of 

 taste and directly by ideas associated with food. 



The nerves The cerebral fibres for the submaxillary gland are 



which influ- contained in the chorda tympani, a branch of the facial 

 ence the sub- nerve. It also receives fibres from the sympathetic. 

 The former according to Heidenhain's theory are 

 mainly secretory, and the latter mainly trophic (meta- 

 bolic), but there is some doubt (Langley) whether the difference 

 observed between them may not be due to the concurrent difference 

 in the blood supply. 



Mode of ob- In man, the submaxillary saliva may be collected 



taming sub- by introducing a silver cannula into the entrance of 



maxillary Wharton's duct in the mouth ; in the lower animals, 



especially the dog, by cutting down upon the duct and 



tying a silver cannula into it. 



Fig. 1. M, anterior portion of the digastric muscle, of which the posterior portion 

 has been removed, and the attachment to the temporal bone cut through at M f . G, sub- 

 maxillary gland raised by means of a hook so as to shew its deep surface. H, ducts of 

 the submaxillary and sublingual ducts ; the former may be traced back to its gland. J, 

 trunk of the external jugular vein. J', a branch of the external jugular vein passing to 

 the back of the gland. J", a branch of the jugular passing to the front of the gland 

 cut across. D, a venous trunk issuing from the submaxillary gland and joining the 

 external jugular vein, t, t', external carotid artery accompanied by two filaments of 

 the sympathetic nerve. F, origin of the inferior artery of the gland. P, hypo- 



