THE HEAD AND NECK I185 



Several important structures traverse the gland, (i) The external 

 carotid artery ascends deeply in it as high as the level of the neck 

 of the inferior maxilla, where it divides into the superficial temporal 

 and internal maxillary arteries, which are at first embedded in the 

 gland. Whilst in the gland the superficial temporal artery gives 

 off its transverse facial and auricular branches. (2) The super- 

 ficial temporal and internal maxillary veins unite in the gland, at 

 the level of the neck of the inferior maxilla, to form the temporo- 

 maxillary vein, which descends from that level within the gland, 

 lying superficial to the external carotid artery, and close to the 

 lower border of the gland it breaks up into an anterior and a pos- 

 terior division. (3) The external jugular vein is formed in the lower 

 part of the gland by the union of the posterior auricular vein with 

 the posterior division of the temporo-maxillary vein. (4) The 

 facial nerve traverses the gland from behind forwards, and, in doing 

 so, breaks up into its temporo-facial and cervico-facial divisions, 

 the branches of which emerge from the gland anteriorly and 

 superiorly. The nerve is superficial to the external carotid artery 

 and temporo-maxillary vein. (5) Entering the lower part of the 

 gland are branches of the great auricular nerve, which communicate 

 within the gland with the facial nerve. (6) The auriculo-temporal 

 nerve is related to the deep surface of the upper part of the gland, 

 where it gives branches to it which communicate with the facial 

 nerve. 



Parotid Duct. — ^This excretory tube, which feels dense and tough, 

 is usually called the duct of Stensen or Steno. It emerges from 

 the anterior border of the gland, and passes forwards on the masseter 

 muscle, lying fully | inch below the zygomatic arch. In this part 

 of its course it is accompanied, for a short distance, by the pars or 

 glandula socia parotidis, which, with the transverse facial artery, 

 lies above it, whilst the infra-orbital branches of the facial nerv^e are 

 placed below it. After leaving the surface of the masseter muscle the 

 duct dips deeply through the fat covering the buccinator, and pierces 

 that muscle. Thereafter it passes forwards for a very short distance 

 beneath the buccal mucous membrane, which it finally pierces to 

 terminate in a minute opening on a small papilla situated opposite 

 the crown of the second upper molar tooth. The duct is about the 

 size of a crow-quill, its diameter being about | inch, except at its 

 buccal orifice, where it becomes narrow. It is about 2 inches in 

 length, and its course ma}' be indicated by a line drawn from the 

 incisura intertragica, or from the junction of the lobule and cartilage 

 of the auricle, to a point midway between the nostril and the red 

 margin of the upper lip. About the middle third of this line 

 corresponds to the duct. 



Blood-supply. — ^The arteries are derived from (i) the external 

 carotid, (2) the superficial temporal, (3) the transverse facial, and 

 (4) the posterior auricular. 



Lymphatics.. — ^These pass to the superficial and deep cervical 



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