1116 



DIGESTIVE SYSTEM 



glossus, stylohyoid and posterior belly of the digastric. Between this surface 

 and the mylohyoid muscle are the mylohyoid nerve and artery and the sub- 

 mental arter3^ 



The deep portion is a tongue-like process which passes from the deep surface 

 of the submaxillar}' gland around the posterior border of the mylohyoid muscle, 

 and extends forward in company with the duct, under cover of (above) the mylo- 

 hyoid, and in relation with the hyoglossus and genioglossus muscles. At its 

 commencement, the deep process lies just below the submaxillary ganglion and 

 anteriorl}' it gives off the submaxillary duct as it approaches the sublingual gland. 



Structure. — The submaxillary is a racemose gland belonging to the mixed type, some of 

 the acini being serous, others mucous (fig. 867). 



The submaxillary (Wharton's) duct springs from the deep surface of the superficial part 

 of the gland; it passes forward and inward, along the medial surface of the deep lobe, and opens 

 by a small orifice on the summit of a papilla [caruncula sublingualis] by the side of the frenulum 

 of the tongue. It is crossed superficially by the lingual nerve. It hes at first between the mylo- 



FiG. 867. — Section of the Submaxillary Gland of an Adult Man. X 252. (Lewis and 



Stohr.) 



Serous gland cells 



Intercalated duct 



cells 



Secretory duct 



hyoid and hyoglossus; next, between the mylohyoid and genioglossus; and lastly, under cover 

 of the mucous membrane of the mouth, between the genioglossus and the sublingual gland. 

 The duct is about 5 cm. in length, and has comparatively thin walls. It is Uned by columnar 

 epithehum. 



Vessels and nerves. — The arteries to the gland are derived from the external maxiUary 

 (facial) and lingual, and they are accompanied by corresponding veins. 



The nerves. — The submaxillary gland receives its secretory fibres from numerous small 

 sympathetic ganglia situated on the submaxillary duct and in the hilus of the gland, these 

 conveying impulses from the chorda tympani; its sensory branches probably come from the 

 geniculate ganglion, and its sympathetic branches from the cervical sympathetic. 



Variations. — Absence of the gland is a rare anomaly. A case is recorded (Turner) where 

 the submaxillary was placed entirely under cover of the mylohyoid, being closely associated 

 with the .sublingual gland. 



THE SUBLINGUAL GLAND 



The sublingual gland [gl. sul)lingualis] — the smallest of the salivary glands 

 (2 to 3 gm.) is iu reality a group of glands forming an elongated mass in the floor 

 of the mouth under the tongue (fig. 847). Above, it forms a distinct ridge, covered 

 by a fold of muco.sa (plica sublingualis) upon which its ducts open (fig. 86G). It is 

 flattened horn side to sid(^, its lower l)order resting upon the ui)per surface of the 

 mylohyoid, its lateral surface in contact with the sublingual fossa of the mandible, 

 and its medial surface with tlu^ gonioiiyoid, geniohyoglossus, lingual nerve, deep 

 lingual artery and submaxillary duct (fig. 8()8). Anteriorly it touches its fellow of 

 the opposite side, while jw.steriorly it is often related with the deep process of the 



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