398 THE MUSCLES AND FASCIA 



Actions. When deglutition is about to be performed, the pharynx is drawn upward and 

 dilated in different directions, to receive the bolus propelled into it from the mouth. The Stylo- 

 pharyngei, which are much farther removed from one another at their origin than at their inser- 

 tion, draw the sides of the pharynx upward and outward, and so increase its transverse diameter; 

 its breadth in the antero-posterior direction is increased by the larynx and tongue being carried 

 forward in their ascent. As soon as the bolus is received in the pharynx, the Elevator muscles 

 relax, the bag descends, and the Constrictors contract upon the bolus, and convey it gradually 

 downward into the oesophagus. Besides its action in deglutition, the pharynx also exerts an 

 important influence in the modulation of the voice, especially in the production of the higher 

 tones. 



6. The Palatal Region (Fig. 308). 



Levator palati. Palatoglossus. 



Tensor palati. Palatopharyngeus. 



Azygos uvulae. Salpingopharyngeus. 



Dissection (Fig. 308). Lay open the pharynx from behind by a vertical incision extending 

 from its upper to its lower part, and partially divide the occipital attachment by a transverse 

 incision on each side of the vertical one; the posterior surface of the soft palate is then exposed. 

 Having fixed the uvula so as to make it tense, the mucous membrane and glands should be 

 carefully removed from the posterior surface of the soft palate, and the muscles of this part 

 are at once exposed. 



The Levator palati (m. levator veil palatini) is a long, thick, rounded muscle, 

 placed on the outer side of the posterior nares. It arises from the under surface 

 of the apex of the petrous portion of the temporal bone, and from the inner surface 

 of the cartilaginous portion of the Eustachian tube; after passing into the pharynx, 

 above the upper concave margin of the Superior constrictor, it passes obliquely 

 downward and inward, its fibres spreading out into the soft palate as far as the 

 middle line, where they blend with those of the opposite side. 



Relations. By its superficial surface, this muscle is in relation with the Tensor palati, the 

 Superior constrictor, and the Eustachian tube; by its deep surface, with the mucous membrane 

 of the pharynx; posteriorly, with the posterior fasciculus of the Palatopharyngeus, the Azygos 

 uvulae, and the mucous membrane of the soft palate. 



The Tensor palati (m. tensor veil palatini) is a broad, thin, ribbon-like muscle, 

 placed on the outer side of the Levator palati, and consisting of a vertical and a 

 horizontal portion. The vertical portion arises by a flat lamella from the scaphoid 

 fossa at the base of the internal pterygoid plate; from the spine of the sphenoid 

 and from the outer side of the cartilaginous portion of the Eustachian tube; 

 it descends vertically between the internal pterygoid plate and the inner surface 

 of the Internal pterygoid muscle, and terminates in a tendon, which winds around 

 the hamular process, being retained in this situation by some of the fibres of origin 

 of the Internal pterygoid muscle. Between the hamular process and the tendon 

 is a small bursa (bursa m. tensoris veli palati}. The tendon or horizontal portion 

 then passes horizontally inward, and is inserted into a broad aponeurosis, the 

 palatal aponeurosis, and into the transverse ridge on the horizontal portion of 

 the palate bone. 



Relations. By its superficial surface, this muscle is in relation with the Internal pterygoid; 

 by its deep surface, with the Levator palati, from which it is separated by the Eustachian tube 

 and Superior constrictor, and with the internal pterygoid plate. In the soft palate its tendon 

 and the palatal aponeurosis are anterior to those of the Levator palati, being covered by the 

 Palatoglossus and the mucous membrane. 



Palatal Aponeurosis. Attached to the posterior border of the hard palate is 

 a thin, firm, fibrous lamella which supports the muscles and gives strength to the 



