720 ORGANS OF DIGESTION. 



carotid artery, which ascends behind the ramus of the jaw ; the posterior auri- 

 cular artery emerges from the gland 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 vein.s ; a branch, 

 connecting this trunk with the internal jugular, also traverses the gland. It is 

 also 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. 



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

 length. It opens upon the inner surface of the cheek by a small orifice, oppo- 

 site the second molar tooth of the upper jaw ; and from this orifice it may be 

 traced obliquely for a short distance beneath the mucous membrane, and thence 

 through the substance of the Buccinator muscle, and across the Masseter to the 

 anterior border of the gland, in the substance of which it commences by nume- 

 rous branches. The direction of the duct corresponds 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 dense, of consider- 

 able thickness, and its canal about the size of a crow-quill ; it consists of an 

 external or fibrous coat, of considerable density, containing contractile fibres, 

 and of an internal or mucous coat, lined with columnar epithelium. 



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

 the external carotid, and from the branches of that vessel in or near its sub- 

 stance. The veins follow a similar course. The lymphatics terminate in the 

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

 three lymphatic glands, placed on the surface and in the substance of the 

 parotid. The nerves are derived from the carotid plexus of the sympathetic, 

 the facial, the superficial temporal, the auriculo temporal, and great auricular 

 nerves. 



The Submaxillary gland is situated below the jaw, in the anterior part of the 

 submaxillary triangle of the neck. It is irregular in form, and weighs about 

 two drachms. It is covered by the integument, Platysma, deep cervical fascia, 

 and the body of the lower jaw, corresponding to a depression on the inner sur- 

 face of that bone; and lies upon the Mylo-hyoid, Hyo-glossus, and Stylo-glossus 

 muscles, a portion of the gland passing beneath the posterior border of the 

 Mylo-hyoid. In front of it is the anterior belly of the Digastric; behind, it is 

 separated from the parotid gland by the stylo-maxillary ligament, and from the 

 sublingual gland in front by the Mylo-hyoid muscle. The facial artery lies 

 imbedded in a groove in its posterior and upper border. 



The duct of the submaxillary gland (W barton's) is about two inches in 

 length, and its walls are much thinner than those of the parotid duct. It opens 

 by a narrow orifice on the summit of a small papilla, at the side of the frasnum 

 linguae. Traced from thence, it is found to pass between the sublingual gland 

 and the Genio-hyo-glossus muscle, then backwards and outwards between the 

 Mylo-hyoid, and the Hyo-glossus and Genio-hyo-glossus muscles, and beneath 

 the gustatory nerve, to the deep portion of the gland, where it commences by 

 numerous branches. 



Vessels and Nerves. The arteries supplying the submaxillary gland are 

 branches of the facial and lingual. Its veins follow the course of the arteries. 

 The nerves are derived from the submaxillary ganglion, from the mylo-hyoid 

 branch of the inferior dental, and from the sympathetic. 



The Sublingual gland is the smallest of the salivary glands. It is situated 



