654 



ORGANS OF DIGESTION. 



gold muscles. Its outer surface, slightly tabulated, is covered by the integument 

 and fascia, and has one or two lymphatic glands resting on it. Its inner surface 

 extends deeply into the neck, by means of two large processes, one of which dips 

 behind the styloid process, and projects beneath the mastoid process and the 

 Sterno-mastoid muscle ; the other is situated in front of the styloid process, and 

 passes into the back part of the glenoid fossa, behind the articulation of the lower 

 jaw. Imbedded in its substance is the external carotid, which ascends behind 

 the ramus of the jaw ; the posterior auricular artery emerges from it behind ; the 

 temporal artery above ; the transverse facial in front ; and the internal maxillary 

 winds through it inwards, behind the neck of the jaw. Superficial to the external 

 carotid is the trunk formed by the union of the temporal and internal maxillary 

 veins; a branch-, connecting it with the internal jugular, also traversing the 

 gland. It is traversed, from before backwards, by the facial nerve and its 

 branches, which emerge at its anterior border ; the great auricular nerve pierces 

 the gland to join the facial, and the temporal branch of the inferior maxillary 

 nerve lies above the upper part of the gland. The internal carotid artery and 

 internal jugular vein lie close to its deep surface. 



Steno's duct, the duct of the parotid gland, is about two inches and a half in 

 length. It commences upon the inner surface of the cheek by a small orifice, 



Fig. 330. The Salivary Gland. 



opposite the second molar tooth of the upper jaw ; running obliquely for a short 

 distance beneath the mucous membrane, it pierces the Buccinator muscle, and 

 crosses the Masseter to the anterior border of the gland, in the substance of 

 which it subdivides into numerous branches. The direction of the duct corre- 

 sponds to a line drawn across the face about a finger's breadth below the zygoma, 

 from the lower part of the concha to midway between the free margin of the 

 upper lip and the ala of the nose. While crossing the Masseter, it receives the 

 duct of a small detached portion of the gland, soda parotidis, which occasionally 

 exists as a separate lobe, just beneath the zygomatic arch. The parotid duct is 



