PLATE LI. NATURAL SIZE. 



THE PHARYNX OPENED SHOWING PALATE, POSTERIOR 



NARES, &c. 



In this dissection the constrictor muscles were divided along the median raphe and 

 the pharyngeal aponeurosis partly detached from its upper attachment ; the mucous 

 membrane was carefully removed from the soft palate and pharynx. On the left side 

 the posterior layer of the palato-pharyngeus was partially turned back, while on the 

 right it was completely removed. The right levator palati was also divided, and the 

 pharyngeal aponeurosis removed from the border of the pterygoid process, in order to 

 expose the tensor palati. 



The position of the tensor and levator palati muscles should be carefully studied, af 

 they have to be divided in operations for cleft palate, because they are concerned in 

 drawing apart the edges of the cleft ; thus causing tension on the stitches when the 

 edges are sutured together. 



The enervation of the levator palati has given rise to much discussion, but Horsley 

 and Bcevor have discovered that stimulation of the facial within the skull produces no 

 effect on the palate, while as soon as the eleventh nerve was stimulated, that side of the 

 soft palate was at once raised. The nerve supply probably reaches it through the 

 pharyngeal plexus. 



In the early foetus the anterior pillar of the fauces is a sharp fold bounding a deep 

 recess which was the lower part of the second post-oral cleft ; the tonsil is a moss of 

 adenoid tissue developed in the cleft, and above it there is often a fossa the supra- 

 tonsillar fossa which is a permanent remains of the cleft. The posterior pillars of the 

 fauces are developed kier, and divide this pouch into the supra-tonsillar fosea and the 

 lateral recess of the pharynx. 



