300 ORGANS OF INSALIVATION. 



ramus of the jaw, extends back to the styloid process, which, 

 with its muscles, it envelops is in contact with the inter- 

 nal carotid artery, jugular vein, and eighth pair, or par- 

 vagum nerves, and finally fills the posterior part of the* 

 glenoid cavity of the temporal bone. 



Each of the granules composing this gland has, as 

 already stated, an excretory duct, which, uniting with its 

 fellows, forms one common duct called the parotid duct, or 

 the duct of Steno, which is seen issuing from the gland at 

 its anterior and posterior part, and is then traced passing 

 over the masseter, about an inch below the zygoma, and 

 through a quantity of soft lobulated fat, on the anterior 

 edge of this muscle. It then pierces the buccinator at 

 its upper part, opening into the mouth by a papilla (some- 

 times there is none) opposite the second or third molar 

 tooth of the upper jaw. 



A line drawn from the lobe of the ear to a point midway 

 the root of the nose and lower margin of the upper lip, 

 will give the direction of the parotid duct. This duct has 

 two coats an outer of condensed cellular, and an inner of 

 mucous membrane. Between the zygoma and this duct, a 

 small glandular mass is occasionally seen, having a small 

 duct which either unites with the duct of Steno, or enters 

 separately into the mouth. It is called the socia parotidis. 



Function. The use of this gland is to secrete the larger 

 portion of the saliva with which the mouth is supplied, 

 and which is carried thither by the duct of Steno. 



2. The Submaxillary Gland (Fig. 85.) 



Dissection. Make an incision along the base of the lower 

 jaw, from the chin back to the angle, and along the ramus, 

 the same as for the organs of prehension. Make a second 

 incision along the median line at the upper part of the 

 neck as far as the hyoid bone, commencing at the lower 

 portion of the symphysis menti, and turn down the skin 

 obliquely towards the clavicle. This exposes the broad 

 muscle of the neck, the platysma myoides, and the superfi- 

 cial cervical fascia. Turn these down, and the submaxil- 

 lary gland is exposed. This gland is second in size to the 



