PHARYNX 295 



and a lower, between which are enclosed the corresponding 

 muscle of the uvula and the levator of the soft palate. 



The upper layer is very weak and confined to the posterior 

 part of the velum. It constitutes the most superficial muscular 

 stratum on the upper aspect of the soft palate, and becomes 

 continuous with the corresponding portion of the muscle of 

 the opposite side. The deeper layer takes origin from the 

 posterior margin of the palate bone and from the palatal 

 aponeurosis, and some of its fibres mingle with those of the 

 corresponding muscle of the' opposite side. Lateral to the 

 soft palate the two strata blend, and are joined by one or two 

 delicate muscular slips which spring from the lower border of 

 the cartilage of the auditory tube. Those slips are some- 

 times described as the salpingo-pharyngeus muscle. The three 

 parts blend at the postero-lateral border of the soft palate, 

 and from there the pharyngo-palatinus passes downwards and 

 backwards in the pharyngo-palatine arch, and spreads out 

 into a thin sheet of fibres in the wall of the pharynx. The 

 pharyngo-palatinus blends, to some extent, with the stylo- 

 pharyngeus, and is inserted, with the stylo-pharyngeus, into the 

 posterior border of the thyreoid cartilage. Some of its fibres, 

 however, incline backwards and are inserted into the pharyngeal 

 aponeurosis. It helps to close the isthmus of the pharynx and 

 to elevate the larynx; it is supplied by the accessory nerve. 



Musculi Uvulae. The two small muscles of the uvula, 

 right and left, lie in the upper part of the soft palate, covered 

 on their upper surfaces by the upper parts of the pharyngo- 

 palatine muscles, which must be removed before the muscles 

 of the uvula can be seen. Each muscle of the uvula is a 

 minute slip which springs from the posterior nasal spine. 

 As they pass backwards the two slips blend, and their fibres 

 are inserted into the mucous membrane of the uvula. They 

 are supplied by the accessory nerve, and when they contract 

 they elevate the uvula. 



Dissection. The levator veli palatini muscle has been seen 

 already, on the outer aspect of the pharynx, in the sinus of 

 Morgagni (Fig. 1 07) . To display it from the inside it is necessary to 

 remove the mucous membrane, the submucous tissue, and the 

 membranous part of the wall of the pharynx between the auditory 

 tube, above, and the upper border of the superior constrictor, 

 below ; afterwards the fibres of the muscle must be followed 

 into the -soft palate where it lies between the two layers of the 

 pharyngo -palatine muscle. In a well-injected subject the dissector 

 in 19 6 



