STRUCTURE OF THE SALIVARY GLAXDS. 



339 



Wharton. One, longer than the rest (which is occasionall.y derived 

 in part also from the snl)maxillary gland), runs along the Whartonian 

 duct, and opens either with it or very near it ; this has been named 

 the duct of Bartholin. 



The blood-vessels of this gland are supplied by the sublingual and submental 

 arteries and veins. The nerves are numerous, and are derived from the lingual 

 branch of the fifth. 



STRUCTURE OF THE SALIVARY GLANDS. 



These glands are constructed on the compound racemose type. Their 

 ducts (traced backwards), after branching a certain number of times, 

 terminate in moderately fine ramuscules, around which the terminal 

 recesses of the gland are grouped, and into which they open. These 

 terminal recesses, saccules, or alveoli (fig. 238 h) are lined and almost 



Fig. 23S. 



Fig. 238. —Section op the Submaxillary Gland of the Dog, stained with carmine. 

 Highly magnified (Kolliker). 



a, cross-section of small salivaiy duct ; b, an alveolus containing salivary cells ; c, 



semilunar body. 



filled by an epithelium, the cells of which {saJivary cells) are spheroidal 

 in form, with flattened sides where they touch one another, and consist 

 each of granular protoplasm enclosing a nucleus, which, in sections, 

 generally appears flattened up against the base of the cell. This position 

 of the nucleus is, however, produced after death ; in the unaltered con- 

 dition it occupies a more central position in the cell (as shown in fig. 240). 



In the submaxillary gland (and also, to a less extent, in the sublingual, but 

 never in the parotid) the salivary-cells for the most part contain mucus, and the 

 swelling up of this by imbibition of water is not improbably the cause of the 

 altered position of the nucleus, as happens in the formation of goblet-cells from 

 columnar epithelium. 



When isolated, the salivary cells not unfi^equently exhibit processes, 

 one from the base of each cell : according to Kolliker the projection 

 is flattened and overlaps the base of a neighbouring cell. A similar 

 relation of the alveolar cells has also been pointed out in Brunner's 

 glands of the intestine, which belong to the same class as the salivary 

 glands (Schwalbe). 



