THE SUBMAXILLARY GLAND 



1115 



Duct, vessels and nerves. — The duct of the parotid (Stenson's) issues from the anterior bor- 

 der of the gland, crosses the masseter a finger's breadth below the zygoma, and turns abruptly 

 medialward round its anterior border. It penetrates the fat of the cheek and the fibres of 

 the buccinator muscle, between w'hich and the mucous membrane it runs for a short distance 

 before it terminates, sometimes on the summit of a little papilla, by a minute orifice. This 

 opening is placed opposite the crown of the second upper molar tooth. The duct commences 

 by numerous branches, which converge toward the anterior border of the gland, and receives 

 in its passage across the masseter the duct of the accessory parotid gland. The canal is about 

 the size of a crow-quill, length about 35 to 40 mm., diameter 3 mm. Its mucous membrane 

 is covered for a short distance, beginning with its oral termination, by stratified pavement 

 epithelium, for the remainder of the distance by columnar epithelium. The coat of the duct 

 is thick and tough, and consists of fibrous tissue intermixed with nonstriated muscle-fibres. 



The arteries are derived from those lying in the gland substance and from the posterior 

 auricular artery. 



The veins terminate in the posterior facial (temporo-maxillary) trunk. 



The nerves. — The parotid gland receives its secretory fibres from the otic ganglion, con- 

 veying impulses from the glosso-pharyngeal via the lesser petrosal and the auriculo-temporal; 

 its sensory supply through branches of the fifth nerve; and its sympathetic supply from the 

 carotid plexus. The lymphatics from the parotid gland terminate in the superficial and deep 

 cervical glands, especially in the deeper group of parotid nodes embedded in the substance of 

 the gland. 



Variations. — ^The parotid is quite variable in size and in the form of its various processes, 

 especially of the accessory lobe, as already mentioned. The lobulations are less distinct in 

 infancy. Rarely the parotid is confined to the masseteric region, the retro-mandibular fossa 

 being filled with a fatty tissue enclosing the vessels and nerves normally found with the gland. 



THE SUBMAXILLARY GLAND 



The submaxillary gland [gl. submaxillaris] weighs 7 to 10 grams, and is of 

 about the form and size of a flattened walnut. It consists of a chief or superficial 

 part, and a smaller deep process. The chief portion is located in the digastric 

 triangle, and presents three surfaces — superficial, deep and lateral (figs. 847, 866). 



Fig. 866. — Medial View of the Sxjbm.\xillary and Sublingual Glands. (Sobotta — 



McMurrich's Atlas.) 



Sublingual caruncle Ductus sublingualis major Minor sublingual ducts 



\ ' n Oral mucosa 



* Submaxillary ducts 



Orbicularis oris*^; 

 Labial gland s 



Sublingual ^ 



gland 



Mandible 



Genio-glossus 



Lingual nerve 

 s^3i33 ,Deep process of 

 submaxillary 



Genio-hyoideus 



Mylo-hyoideus 



--:::^. 



Submaxillary 

 gland 



-J^ 



Surfaces. — The superficial or latero-inferior surface is covered by skin, super- 

 ficial fascia, platysma and deep fascia (which forms an incomplete capsule around 

 the gland). It is crossed by the facial vein and by cervical branches of the facial 

 nerve. Several h-mphatic glands, which receive vessels from the anterior facial 

 region, lie upon or embedded in this surface. 



The lateral surface is the smallest of the three. It is in contact with the sub- 

 maxillary fossa of the medial surface of the mandible, and with the lower part of 

 the internal pterygoid muscle. The posterior aspect of the gland is deepty 

 grooved by the external maxillary (facial) artery and is separated from the parotid 

 gland by the stylo-mandibular ligament. The deep or medio-superior surface is 

 in contact with the lower surface of the mylohyoid, and behind this with thehyo- 



