816 THE SALIVARY GLANDS. 



and styloid muscles ; and, in front, under cover of the ramus of the jaw, it 

 advances a certain distance between the external and internal pterygoid 

 muscles. 



The internal carotid artery and internal jugular vein are close to the deep 

 surface of the gland. The external carotid artery, accompanied by the tem- 

 poral and internal maxillary veins, passes through the parotid gland ; and in 

 that situation arise the temporal and internal maxillary arteries, as also the 

 auricular and transverse facial branches of the temporal. The gland is also 

 traversed by the facial nerve, which divides into branches within its sub- 

 stance, and it is pierced by branches of the great auricular nerve. 



The parotid duct, named also Stenson's duct (d. Stenonianus), appears at 

 the anterior border of the gland, about one finger's breadth below the zygoma, 

 and runs forwards over the masseter muscle, accompanied by the socia paro- 

 tidis, when that accessory portion of the gland exists, and receiving its ducts. 

 At the anterior border of the masseter, the duct turns inwards through the 

 fat of the cheek and pierces the buccinator muscle ; and then, after running 

 for a short distance obliquely forwards beneath the mucous membrane, opens 

 upon the inner surface of the cheek, by a small orifice opposite the crown of 

 the second molar tooth of the upper jaw. Its direction across the face may 

 be indicated by a line drawn from the lower margin of the concha of the ear 

 to a point midway between the red margin of the lip and the ala of the nose. 

 The length of the Stenonian duct is about two inches and a half, and its 

 thickness about one line and a half. At the place where it perforates the 

 buccinator, its canal is as large as a crow-quill, but at its orifice it is smaller 

 than in any other part, and will only admit a very fine probe. The duct is 

 surrounded by areolar tissue, and consists of an external, dense, and thick 

 fibrous coat, in which contractile fibres are described, and of an internal 

 mucous tunic, which is continuous with that of the mouth, but which is 

 covered, from the orifice of the duct as far as to the smallest branches, with 

 a columnar epithelium. 



The parotid gland belongs to the class of compound racemose glands, and 

 consists of numerous flattened lobes, held together by the ducts and vessels, 

 and by a dense areolar web, which is continuous with the fascia upon its outer 

 surface ; but the gland has no special or proper coat. The lobes are again 

 divided into lobules, each of which consist of the branched terminations of 

 the duct, and of vessels, nerves, and fine areolar tissue. The ducts termi- 

 nate in closed vesicular extremities, about ^^th of an inch or more in 

 diameter, which are lined with epithelium, and have capillary vessels 

 ramifying upon them. 



The vessels of the parotid gland enter and leave it at numerous points. The arteries 

 are derived directly from the external carotid, and from those of its branches which 

 pass through or near the gland. The veins correspond. The absorbents join the deep 

 and superficial set in the neck ; and there are often one or more lymphatic glands 

 imbedded in the substance of the parotid. The nerves come from the sympathetic 

 (carotid plexus), and also, it is said, from the facial and the superficial temporal and 

 great auricular nerves. 



An instance is recorded by Gruber of a remarkable displacement of the parotid on 

 one side ; the whole gland being situated on the masseter muscle as if it were an 

 enlarged socia parotidis. (Virchow's Archiv, xxxii., p. 328.) 



The Submaxillary Gland. 



The submaxillary gland, the next in size to the parotid gland, is of a 

 spheroidal form, and weighs about 2 or 2|- drachms. It is situated imme- 



