158 



TEXT-BOOK OF PHYSIOLOGY. 



INSALIVATION. 



Insalivation is the incorporation of the saliva with the food, and 

 takes place for the most part during mastication. The saliva ordi- 

 narily present in the mouth is a complex fluid composed of the various 

 secretions of the parotid, submaxillary, and sublingual glands and 

 the muciparous follicles of the mouth, which collectively constitute 

 the salivary apparatus (Fig. 61). 



The parotid gland is situated in front of and partly below the 



external ear, where it is 

 llj^ held in position by the 



fascia and skin. From the 

 anterior border of the gland 

 there emerges a duct (Sten- 

 sen's), which, after crossing 

 the masseter muscle to its 

 anterior border, turns in- 

 ward, pierces the buccin- 

 ator, a.nH^njwpa ftn % snr- 

 face of the cheek opposite 

 the second upper molar 

 tooth// 



The submaxillary 

 gland is situated below the 

 jaw in the anterior part of 

 the submaxillary triangle. 

 From the gland there 

 emerges a duct (Wharton's) 

 which/^pens into the mouth 

 by a minute orifice on the 

 surface of a papilla by the 

 side of the tongue^ 



""The sublingual gland 

 is situated just beneath the 

 mucous membrane in the 

 anterior part of the mouth, 

 where it forms a projection 



between the gums and tongue. The posterior part of the gland 

 gives origin to a duct (the duct of Rivinus, described also by Bartho- 

 lin)^which opens into the mouth with or very near to the duct of 

 Wriarton./ The anterior part of the gland gives origin to a varying 

 number of ducts (Walthers) which open separately along the edge of 

 the sublingual plica of the mucous membrane. 



Histologic Structure of the Salivary Glands. In their ulti- 

 mate structure the salivary glands bear a close resemblance to one 



FIG. 61. SALIVARY GLANDS, i, 2. Parotid. 

 3. Duct of Steno. 4. Submaxillary. 5. 

 Sublingual. 6. Mylohyoid muscle. 7. 

 Lingual branch of the fifth nerve. 8. Duct 

 of Wharton. 9. Digastric muscle. 10. 

 Sternomastoid muscle, n. External jugu- 

 lar vein. 12. Facial vein. 13. Temporal 

 vein. 14, 15. Internal jugular vein. 16. 

 Branch of the cervical plexus. 17. Sub- 

 lingual nerve. (Le Bon.} 



