

SALIVAKY GLANDS. 



1139 



Each lies immediately below the mucous membrane of the floor of the mouth, 

 between the tongue and the gum of the mandible, and there it causes the elevation 

 on the floor of the mouth termed the plica sublingualis. 



When the mucous membrane is removed from this region, the gland is found 

 to be lying in the interval between the sublingual fossa (on the inner surface of 

 the mandible above the mylo-hyoid line) and the genioglossus muscle, which 

 passes from the mandible to the tongue. Below, it rests upon the deep surface 

 of the mylo-hyoid muscle. 



In shape it is almond-like, flattened from side to side, but is much wider (from 

 above downwards) anteriorly than posteriorly. It is usually from 1 J to 1 j inches (37 

 to 45 mm.) in length, whilst its bulk is about equal to that of two or three almonds. 



Its detailed relations are as follows : Its lateral surface rests against the inner aspect 

 of the body of the mandible above the mylo-hyoid line. Its medial surface is in contact with 

 the genioglossus, styloglossus, and hyoglossus muscles, as well as with the submaxillary 



Crescent of Gianuzzi 

 Mucous cell 



Lumen 



Nucleus of mucous cell 



Framework of gland 



Fibrous capsule 



Granules in serous cell 



B 



FIG. 900. 

 Section of human submaxillary gland x 400. B. Section of human parotid gland x 400. 



duct, which runs forwards between the gland and the muscles. Below, it rests on the 



mylo-hyoid, and at its posterior part on the deep process of the submaxillary gland ; whilst 

 I its upper prominent border is covered only by the mucous membrane of the mouth, here 

 ; raised up by the gland to form the plica sublingualis (Fig. 892). The anterior portion of 



the gland is much deeper and more bulky than the posterior half, and it meets its fellow 

 | in the median plane beneath the frenulum linguae. The posterior extremity grows gradually 



more slender, but may extend to the posterior part of the mylo-hyoid ridge, where it lies 

 : above the deep process of the submaxillary gland. 



Its ducts, generally known as the ductus sublinguales minores (O.T. ducts of 

 Rivinus), are about twelve in number and of small size ; they leave the superior 

 part of the gland, and, after a short course, open on a series of papillae, visible to 

 the naked eye, which are placed along the summit of the plica sublingualis. 



The gland is not enclosed in a distinct capsule, thus differing from the parotid and submaxil- 

 lary glands ; but its numerous lobules, which are smaller than those of the glands just mentioned, 

 e held together by fine connective tissue, loosely, but still in such a manner as to make one 

 more or less consolidated mass out of what was, in the embryo, a number of separate glands. 



.s a rule all the ducts open separately on the summit of the plica sublingualis, and appar- 

 ently none of them join the submaxillary duct. Frequently some of those from the anterior and 

 nore bulky part of the gland are larger than the others, but the presence of a large duct 

 running alongside of the submaxillary duct, and opening with or beside it, ductus sublingualis 



73 a 



