THE SALIVARY GLANES 



393 



Lymphatics. Lymphatics are relatively few and are for the most 

 part confined to the interlobular septa, where they form cleft-like spaces 

 which lead to true lymphatic vessels and so on to the lymph nodes of the 

 cervical region. 



Nerve Supply. The salivary glands are abundantly supplied with 

 nerves, which are derived from both sympathetic and cerebral trunks. 

 They are distributed to the walls of the blood-vessels and ducts, and 

 to the secreting cells of the acini. The nerve trunks are found in the 

 interlobular connective tissue where 

 they are supplied with small ganglia 

 which are most abundant in the sub- 

 maxillary and least numerous in the 

 parotid gland. 



The sympathetic fibers which inner- 

 vate the blood-vessels proceed from the 

 superior cervical ganglion. They are 

 believed to be vasodilator fibers. The 

 cerebral nerves, which supply fibers to 

 the gland cells, are the facial and the 

 glossopharyngeal. The parotid gland 

 is supplied by the glossopharyngeal ; 

 the fibers (secretory and vasoconstric- 

 tor) passing by way of the tympanic 



nerve (nerve of Jacobson), small superficial petrosal, otic (sympathetic) 

 ganglion, and the auriculotemporal branch of the inferior maxillary 

 division of the trigeminal nerve. The submaxillary and sublingual 

 glands receive their secretory fibers and vasoconstrictor fibers from the 

 trigeminal nerve, by way of the chorda tympani nerve and the submaxil- 

 lary (sympathetic) ganglion. The fibers beyond the otic and submaxil- 

 lary ganglia are believed to be true postganglionic fibers; that is, axons 

 of cell bodies situated in these ganglia. Sensory fibers are said to pass 

 to the ducts. 



Delicate fiber bundles from the interlobular nerve trunks enter the 

 lobules and form a plexus of naked fibrils about the walls of the acini, 

 known as the epilemmal plexus, from which terminal fibrils pierce the 

 basement membrane and as hypolemmal fibers end in contact with and 

 between the secreting cells. Small terminal expansions, varicosities, or 

 end knobs are found in the course of the hypolemmal fibers. 



FIG. 364. NERVE ENDINGS IN A 

 SALIVARY GLAND. 



H, demilune; I, secreting acini; 

 n, nerve fibrils. Highly magnified. 

 (After Retzius, from Rauber.) 



