DISSECTION OP THE HEAD AND NECK. 169 



THE PAEOTIDEAL REGION. 



The Parotid Gland (Plates 27, 29, and 30). This is the largest of the 

 salivary glands. It derives its name from its proximity to the ear, below 

 the root of which it is placed. From that point it stretches downwards, 

 filling up the space between the wing of the atlas and the edge of the 

 vertical ramus of the inferior maxilla. The outer surface of the gland is 

 flat, and is separated from the skin by the parotido-auricularis muscle, 

 and by the continuation of the cervical panniculus, which here takes 

 the form of an aponeurosis with scattered muscular bundles. The 

 jugular vein lies in a depression on the lower half of this surface, after 

 having become superficial by passing through the substance of the 

 gland. Below and behind the ear the posterior auricular vein is visible 

 for some distance before it passes into the gland to join the jugular. 

 Finally, the outer surface is crossed obliquely upwards and forwards by 

 the auricular branches of the 2nd cervical nerve, and obliquely down- 

 wards and backwards by the cervical filament of the 7th cranial nerve, 

 which comes out through the gland at the same point as the jugular, 

 and descends under cover of the parotido-auricularis and panniculus 

 muscles to be continued along the jugular channel of the neck. 

 The anterior edge of the gland is related to the border of the vertical 

 ramus, which it overlaps slightly. This edge is most intimately 

 adherent to the bone and to the masseter mtiscle, and at it the facial 

 branches of the 7th and 5th cranial nerves, and the transverse facial and 

 maxillo-muscular vessels pass on to the face by emerging between the 

 gland and the bone, or by perforating the edge of the former. The pos- 

 terior edge of the gland is related to the edge of the wing of the atlas 

 covered by the mastoido-humeralis muscle, and the connection between 

 them is merely by loose areolar tissue. The upper extremity of the gland 

 is notched to embrace the root of the ear, and beneath or through it the 

 auricular nerves and arteries pass to the ear. The inferior extremity of 

 the gland is margined by the submaxillary vein, which joins the jugular 

 beneath the postero-inferior angle of the gland. The deep face of the 

 gland has numerous and important relationships, which will be exposed 

 by the removal of the gland ; but its duct must first be examined. 



Stenson's Duct. This is formed as a single duct by the union of 

 secondary branches at the anterior edge of the gland, a little above its 

 lower extremity. It crosses over the tendon of the sterno-maxillaris 

 muscle, and enters the intermaxillary space, where it will subsequently 

 be followed. 



Directions. — The parotid gland should now be removed in order to 

 expose the objects beneath it. Its removal must be effected with great 

 care, so as to leave, as far as possible, the vessels and nerves which lie 

 beneath it, or pass through its substance. This will be best done by 



