PHARYNX 373 



From this somewhat extensive origin, the fibres curve postero- 

 medially to reach the median raphe, whilst, as a rule, some 

 of the highest gain a distinct insertion into the pharyngeal 

 tubercle on the under surface of the basi-occipital bone. 



The lower part of the superior constrictor is overlapped 

 by the middle constrictor, and the stylo-pharyngeus passes into 

 the interval between the two as it descends to its insertion 

 (Fig. 148, n). The upper border of the muscle, which is 

 free and crescentic, falls short of the basis cranii. 



Raphe Pterygo-mandibularis (Fig. 148, </). This is a 

 strong, narrow, tendinous band, which extends from the 

 hamulus of the medial pterygoid lamina to the posterior 

 part of the mylo-hyoid ridge of the mandible. It acts as 

 a tendinous bond of union between the buccinator and 

 superior constrictor muscles, and its connections can be 

 appreciated best by introducing the finger into the mouth 

 and pressing laterally along the course of the raphe. 



Sinus of Morgagni. This name is applied to the semi- 

 lunar space which intervenes between the upper crescentic 

 margin of the superior constrictor and the basis cranii. 

 The deficiency in the muscular wall of the pharynx in this 

 region is compensated for by the increased strength of the 

 pharyngeal aponeurosis, which, in this situation, is called the 

 pharyngo-basilar fascia. In contact with the outer surface of 

 the aponeurosis are two muscles belonging to the soft palate 

 viz. the levator veil palatini and the tensor veil palatini (Fig. 

 148, c and b\ The levator, which is rounded and fleshy, lies 

 posterior to the tensor, which is flat and more tendinous. 

 The tensor can readily be recognised from its position in 

 relation to the deep surface of the internal pterygoid muscle 

 and from its tendon turning medially under the hamulus of 

 the medial pterygoid lamina. In the upper part of the space, 

 close to the basis cranii and between the origin of the two 

 muscles, will be seen the auditory tube (O.T. Eustachian tube). 



Pharyngeal Aponeurosis. The upper part of the pharyn- 

 geal aponeurosis, the pharyngo-basilar fascia^ is strong, and it 

 maintains the integrity of the wall of the pharynx where the 

 muscular fibres are absent. As it is traced downwards it 

 gradually becomes weaker, until it is ultimately lost as a 

 distinct layer. It lies between the muscles and mucous mem- 

 brane and comes to the surface only where the muscles are 

 absent. It is the principal means by which the pharynx is 

 ii 24 a 



