MUSCLES OF THE PHARYNX AND PALATE. 189 



the lower fibres ID dining downwards beneath the inferior constrictor, the 

 highest ascending and overlapping the superior constrictor, and the interme- 

 diate fibres running transversely. 



This muscle is separated from the superior constrictor by the stylo-pharyngeus 

 muscle and the glosso-pharyngeal nerve, while between its origin and that of the 

 inferior constrictor the superior laryngeal nerve pierces the thyro-hyoid membrane. 



Fibres of the middle constrictor have been observed to arise from the body of the 

 os hyoides, and the thyro-hyoid ligament (syndesmo-pharyngeus of Douglas), and a 

 few are frequently continued into it from the genio-hyo-glossus muscle. The two 

 middle constrictors have been found connected behind to the base of the skull by a 

 fibrous band (Albiiius). 



The superior constrictor arises by fibres attached in series from below 

 upwards, a few to the side of the tongue, and others to the mucous mem- 

 brane of the mouth, to the extremity of the mylo-hyoid ridge of the jaw, to 

 the ptery go- maxillary ligament which separates this muscle from the bucci- 

 nator, and to the lower third of the internal pterygoid plate. From these 

 different points the fibres of the muscle curve backwards, and are mostly 

 blended with those of the corresponding muscle aloug the middle line, a 

 few ending posteriorly in the aponeurosis which fixes the pharynx to the 

 base of the skull. The upper margin curves round the levator palati inollis 

 and the Eustachian tube ; and the space intervening between this concave 

 margin of the constrictor and the base of the skull is closed by fibrous 

 membrane. 



In contact with the outer surface of this muscle are the internal carotid artery, with 

 the eighth and other larger nerves ; the middle constrictor, which overlaps a consider- 

 able portion ; and the stylo-pharyngeus, which descends to the pharynx between the 

 two constrictors. It conceals the palato-pharyngeus and the tonsil, and is lined by 

 mucous membrane. 



The stylo-pharyngeus, larger and longer than the other styloid muscles, 

 arises from the inner surface of the styloid process, near the root, and pro- 

 ceeding downwards and inwards to the side of the pharynx, passes under 

 cover of the middle constrictor muscle, where it detaches some fibres to the 

 constrictors, and, gradually expanding, is connected with the palato-pharyn- 

 geus muscle, and ends in the superior and posterior borders of the thyroid 

 cartilage. 



The external surface of this muscle is, in the upper part of its extent, in contact 

 with the styloid process, the stylo-hyoideus muscle, and the external carotid artery ; 

 in the lower, with the middle constrictor of the pharynx. Internally it rests on the 

 internal carotid artery and jugular vein; but more inferiorly it is in contact with the 

 mucous membrane of the pharynx. The glosso-pharyngeal nerve is close to the 

 muscle, and crosses over it in turning forwards to the tongue. 



The salpingo-pharyngeus (Santorini) is a small muscle, which, arising from 

 the Eustachian tube, descends in the interior of the pharynx towards its 

 back part, and, after joining with the palato-pharyngeus, is lost in the 

 muscular structure of the cavity. It is often indistinct, and is frequently 

 absent. 



THE SOFT PALATE (velum pendulum palati) is a movable cuitain, continued 

 backwards from the hard palate. It presents posteriorly a free pendulous 

 margin, prolonged in the middle into a conical process, the uvula, and at 

 each side into two prominent curved lines, the anterior of which, the anterior 

 pillar of the fauces, descends to the side of the tongue, while the posterior 

 line, the posterior pillar of the fauces, extends into the pharynx : between the 



