THE SALIVARY GLANDS 1227 



off its posterior auricular branch which emerges from the gland behind; it then 

 divides into its terminal branches, the internal maxillary and superficial temporal; 

 the former runs inward behind the neck of the mandible; the latter runs upward 

 across the zygoma and gives off its transverse facial branch which emerges from 

 the front of the gland. Superficial to the arteries are the temporal and internal 

 maxillary veins, uniting to form the temporomaxillary vein; in the lower part of 

 the gland this vein divides into anterior and posterior divisions. The anterior 

 division emerges from the gland to join the facial vein; the posterior unites in the 

 gland with the posterior auricular vein to form the external jugular vein. On a 

 still more superficial plane is the facial nerve, the branches of which emerge at 

 the upper and anterior borders of the gland. Branches of the great auricular 

 nerve pierce the gland to join the facial, and the auriculotemporal branch of the 

 inferior maxillary nerve emerges from the upper part of the gland. 



Lymph nodes, known as the parotid nodes, are in and about the parotid gland, 

 some being embedded in the outer surface of the parotid fascia, others being in 

 tlie inner surface of the fascia, others in the gland itself, particularly along the 

 temporomaxillary vein and external carotid artery (see p. 779). 



'The Duct of the Parotid Gland, or Stenson's Duct (ductus parotideus [Stenonis]) 

 (Fig. 946), is about two inches and a half (6.25 cm.) in length. It commences by 

 numerous branches from the anterior part of the gland, crosses the Masseter 

 muscle, and at its anterior border turns inward nearly at a right angle and passes 

 into the substance of the Buccinator muscle, which it pierces; it then runs for a 

 short distance obliquely forward between the Buccinator muscle, and the mucous 

 membrane of the mouth, and opens upon the inner surfaee of the cheek by a small 

 orifice, opposite the second upper molar tooth (Fig. 926). While crossing the 

 Masseter it receives the duct of the soda parotidis. In this position it has the 

 transverse facial artery above it and some branches of the facial nerve below it. 



The parotid duct is dense, it is of considerable thickness, and its canal is about 

 the size of a crowquill; but at its orifice on the inner aspect of the cheek its lumen 

 is greatly reduced in size. The duct corresponds to the middle third of a 

 line drawn across the face from the lower margin of the external auditory meatus 

 to midway between the red margin of the upper lip and the ala of the nose. 



Vessels and Nerves. The arteries supplying the parotid gland are derived from the ex- 

 ternal carotid, and from the branches given off by that vessel in or near its substance. The 

 veins empty into the external jugular through some of its tributaries. The lymphatics terminate 

 in the superficial cervical and the deep cervical nodes, passing in their course through two or 

 three lymph nodes placed on the surface and in the substance of the parotid. The nerves 

 are derived from the plexus of the sympathetic on the external carotid artery, the nervus inter- 

 medius, the auriculotemporal, and the great auricular nerves. It is probable that the branch 

 from the auriculotemporal nerve is derived from the glossopharyngeal through the otic gan- 

 glion. At all events, in some of the lower animals this has been proved experimentally to be 

 the case. 



The Submaxillary Gland (glandula submaxillaris) (Fig. 946) is irregular in 

 form and weighs about two drams (eight to ten grams). A considerable part 

 of it is situated in the submaxillary triangle, reaching forward to the anterior 

 belly of the Digastric and backward to the stylohyoid ligament which intervenes 

 between it and the parotid gland. Above, it extends under cover of the body 

 of the mandible; below, it usually overlaps the intermediate tendon of the Digastric 

 and the insertion of the Stylohyoid, while from its deep surface a tongue-like 

 deep process extends forward and inward above the Mylohyoid muscle. 



The deep surface is in relation with the Mylohyoid, Hyoglossus, Styloglossus, 

 Stylohyoid, and posterior belly of the Digastric muscles; in contact with it are the 

 mylohyoid nerve and the mylohyoid and submental vessels. 



The facial artery is embedded in a groove in the posterior border of the gland. 



