SALIVARY GLANDS. 503 



The Soft palate (velum pendulum palati) is a fold of mucous membrane, 

 situated at the posterior part of the mouth. It is continuous, superiorly, 

 with the hard palate, and is composed of mucous membrane, palatal 

 glands, and muscles. Hanging from the middle of its inferior border is a 

 small rounded process, the uvula ; and passing outwards from the uvula 

 on each side are two curved folds of the mucous membrane, the arches, 

 or pillars of the palate. The anterior pillar is continued downwards to 

 the side of the base of the tongue, and is formed by the prominence of the 

 palato-glossus muscle. The posterior pillar is prolonged do\vnwards and 

 backwards into the pharynx, and is formed by the convexity of the palato- 

 pharyngeus muscle. These two pillars, closely united above, are sepa- 

 rated below by a triangular interval or niche, in which the tonsil is lodged. 



The Tonsils (amygdalae) are two glandular organs, shaped like almonds, 

 and situated between the anterior and posterior pillar of the soft palate, on 

 each side of the fauces. They are composed of an assemblage of mu- 

 cous follicles, which open upon the surface of the gland. Externally, 

 they are invested by the pharyngeal fascia, which separates them from the 

 superior constrictor muscle and internal carotid artery, and prevents an 

 abscess from opening in that direction. In relation to surrounding parts, 

 they correspond with the angle of the lower jaw. 



The space included between the soft palate and the root of the tongue 

 is the isthmus of the fauces. It is bounded above by the soft palate ; on 

 each side by the pillars of the soft palate and tonsils ; and below by the 

 root of the tongue. It is the opening between the mouth and pharynx. 



SALIVARY GLANDS. 



Communicating with the mouth are the excretory ducts of three pairs 

 of salivary glands, the parotid, submaxillary, and sublingual. 



The Parotid gland, (^a^a, near, oc,, WTO?, the ear,) the largest of the 

 three, is situated immediately in front of the external ear, and extends 

 superficially for a short distance over the masseter muscle, and deeply be- 

 hind the ramus of the lower jaw. It reaches inferiorly to below the level 

 of the angle of the lower jaw r , and posteriorly to the mastoid process, 

 slightly overlapping the insertion of the sterno-mastoid muscle. Embedded 

 in its substance are the external carotid artery, temporo-maxillary vein, 

 and facial nerve; emerging from its anterior border, the transverse facial 

 artery and branches of the pes anserinus ; and above, the temporal artery. 



The duct of the parotid gland (Stenon's* duct) commences at the pa- 

 pilla upon the internal surface of the cheek, opposite the second molar 

 tooth of the upper jaw ; and, piercing the buccinator muscle, crosses the 

 masseter to the anterior border of the gland, where it divides into several 

 branches, which subdivide and ramify through its structure, to terminate 

 in the small caecal pouches of which the gland is composed. A small 

 branch is generally given off from the duct while crossing the masseter 

 muscle, which forms, by its ramifications and terminal dilatations, a small 

 glandular appendage, the soda parotidis. Stenon's duct is remarkably 

 dense and of considerable thickness, while the area of its canal is extremely 

 small. 



The Submaxillary gland is situated in the posterior angle of the sub- 



* Nicholas Stenon, an anatomist of great research. He discovered the parotid ;iuci 

 while in Paris. He was appointed Professor of Medicine in Copenhagen in 1672 His 

 work, " De Musculis et Glandulis Observationes," was published in 1664 



