392 



THE DIGESTIVE SYSTEM 



the parotid. It contains many sympathetic ganglia of relatively large 

 size. Small lamellar corpuscles of simple construction are occasionally 

 found in the interlobular connective tissue (Krause). 



The Sublingual Gland. This is the smallest of the three pairs of 

 large salivary glands. It is not invested by a distinct capsule. It lies 

 under the floor of the mouth anteriorly, one on either side of the frenu- 



lum. It is a mixed gland in man, dog, cat and 

 rabbit. It differs from the submaxillary, how- 

 ever, in that all of its acini are mucous. It be- 

 comes 'mixed' by reason of the presence of very 

 many demilunes (serous cells). Although iso- 

 lated sections which pass through the larger 

 collections of demilune cells may appear as sec- 

 tions of serum-secreting tubules, if examined 

 in longitudinal section or by reconstruction the 

 true mucous character of each lobule is ap- 

 parent. Many of the terminal acini of the 

 sublingual gland, however, although much 

 branched, contain no demilunes. The 'basket 

 cells' are readily recognized in the acini of this 

 gland though they are less highly developed 

 here than in the parotid. Its intralolmlar duct 

 system lacks intermediate ducts, and is largely 

 of the 'salivary' type. 



Accompanying the sublingual gland proper, 

 or larger component, are a variable number (5 

 to 20) of accessory sublingual glands of various 

 sizes. They consist largely of mucous alveoli, each 



gland opening into the mouth by an independent duct. The duct of the 

 sublingual proper (duct of Bartholin) opens at the side of the frenulum. 

 Blood Supply. The salivary glands possess a rich blood supply. 

 The arteries accompany the glandular ducts within the interlobar and 

 interlobular connective tissue, and thus reach all the lobules of the 

 gland. Small arterial twigs enter the lobule from all sides and form a 

 rich capillary plexus in the delicate connective tissue coats of the acini. 

 The capillaries are thus brought into intimate relation with the secreting 

 cells, from which they are only separated by the basement membrane of 

 the acinus. The veins return by a similar course, the smallest venules 

 passing out of the lobule into the connective tissue septa in which they 

 retrace the course of the arteries. 



FIG. 363. RECONSTRUC- 

 TION MODEL OF THE 

 SUBLINGUAL GLAND OP 

 MAN. 



An intralobular duct 

 terminating in salivary 

 ducts and acini. X 285. 

 (After Maziarski.) 



