302 OKGANS OF INSALIVATION. 



Blood-vessels. The salivary glands are abundantly sup- 

 plied with blood-vessels. The arteries going to the parotid 

 come from the external carotid (Fig. 73) and its branches 

 the facial, superficial temporal, transverse facial, and an- 

 terior and posterior auricular. The veins take the same 

 direction as the arteries, .have the same names, and termi- 

 nate in the jugular. The submaxillary is supplied by the 

 facial and lingual. The sublingual gland has its supply 

 from the sublingual and the submental branches. The 

 veins correspond to the arteries. 



Nerves. The parotid is supplied with nerves from the 

 auricular branch of the inferior maxillary, (Fig. 74,) and 

 auricular branch of the cervical plexus; the facial, and 

 filaments of the sympathetic, from those of the external 

 carotid artery. The submaxillary gland is supplied from 

 the submaxillary ganglion, the lingual, and mylo-hyoid 

 branch of the inferior dental nerve. 



Saliva is a term indiscriminately applied to the secre- 

 tions furnished by the salivary glands, and, until very 

 recently, has been supposed to be of the same character, 

 whatever its source. It was generally examined mixed 

 with the other fluids of the mouth, so that its precise char- 

 acter could not be definitely fixed. It was regarded as 

 alkaline, in a state of health, which more recent observa- 

 tions confirm ; while the fluids of the buccal mucous mem- 

 brane have been found to be acid. 



The microscope reports the saliva to contain minute 

 corpuscles, and large epithelial scales derived from the 

 mucous membrane of the mouth. Its chemical constitution 

 is furnished by the chemists Frerichs and Wright, two 

 of the most recent authorities, and whose analysis is re- 

 garded as the most accurate. The former makes saliva to 

 consist in a hundred parts : of water, 994.10; solid matters, 

 5.90; ptyaline, 1.41; mucus and epithelium, 2.13; fatty 

 matter, .07; sulpho-cyanide of potassium, .10; alkaline and 

 earthy chlorides and phosphates, 2.19. 



Wright's analysis is in a hundred parts: water, 988.10; 

 solid matters, 11.90; ptyaline, 1.80; mucus and epithelium, 



