THE PALATAL REGION. 331 



Relations. Anteriorly, with the tendinous expansion of the Levatores palati ; 

 behind, with the posterior fasciculus of the Palato-pharyngeus and the mucous 

 membrane. 



The two next muscles are exposed by removing the mucous membrane frorn the pillars of 

 the fauces throughout nearly their whole extent. 



The Palato-glossus (Constrictor isthmi faucium) is a small fleshy fasciculus, 

 narrower in the middle than at either extremity, forming, with the mucous 

 membrane covering its surface, the anterior pillar of the soft palate. It arises 

 from the anterior surface of the soft palate on each side of the uvula, and, passing 

 downward, forward, and outward in front of the tonsil, is inserted into the side 

 of the tongue, some of its fibres spreading over the dorsum, and others passing 

 deeply into the substance of the organ to intermingle with the Transversus linguae. 

 In the soft palate the fibres of this muscle are continuous with those of the muscle 

 of the opposite side. 



The Palato-pharyngeus is a long, fleshy fasciculus, narrower in the middle than 

 at either extremity, forming, with the mucous membrane covering its surface, the 

 posterior pillar of the soft palate. It is separated from the Palato-glossus by an 

 angular interval, in which the tonsil is lodged. It arises from the soft palate by 

 an expanded fasciculus, which is divided into two parts by the Levator palati and 

 Azygos uvulae. The posterior fasciculus lies in contact with the mucous membrane, 

 and also joins with the corresponding muscle in the middle line ; the anterior 

 fasciculus, the thicker, lies in the soft palate between the Levator and Tensor, and 

 joins in the middle line the corresponding part of the opposite muscle. Passing 

 outward and downward behind the tonsil, the Palato-pharyngeus joins the Stylo- 

 pharyngeus, and is inserted with that muscle into the posterior border of the 

 thyroid cartilage, some of its fibres being lost on the side of the pharynx, and 

 others passing across the middle line posteriorly to decussate with the muscle of 

 the opposite side. 



Relations. In the soft palate its posterior surface is covered by mucous 

 membrane, from which it is separated by a layer of palatine glands. By its 

 anterior surface it is in relation with the Tensor palati. Where it forms the 

 posterior pillar of the fauces it is covered by mucous membrane, excepting on 

 its outer surface. In the pharynx it lies between the mucous membrane and the 

 Constrictor muscles. 



The Salpingo-pharyngeus. This muscle arises from the inferior part of the 

 Eustachian tube near its orifice; it passes downward and blends with the posterior 

 fasciculus of the Palato-pharyngeus. 



In a dissection of the soft palate from its posterior or nasal surface to its anterior 

 or oral surface, the muscles would be exposed in the following order : viz. the 

 posterior fasciculus of the Palato-pharyngeus, covered over by the mucous membrane 

 reflected from the floor of the nasal fossae ; the Azygos uvulae ; the Levator palati ; 

 the anterior fasciculus of the Palato-pharyngeus ; the aponeurosis of the Tensor 

 palati, and the Palato-glossus covered over by a reflection from the oral mucous 

 membrane. 



Nerves. The Tensor palati is supplied by a branch from the otic ganglion ; 

 the remaining muscles of this group are in all probability supplied by the internal 

 branch of the spinal accessory, whose fibres are distributed along with certain 

 branches of the pneumogastric through the pharyngeal plexus. 1 It is possible, 

 however, that the Levator palati may be supplied by the facial through the 

 Petrosal branch of the Vidian. 



Actions. During the first stage of deglutition the morsel of food is driven 

 back into the fauces by the pressure of the tongue against the hard palate, the 

 base of the tongue being, at the same time, retracted, and the larynx raised with 

 the pharynx, and carried forward under it. During the second stage the entrance 

 to the larynx is closed, not, as was formerly supposed, by the folding backward 

 1 Journal of Anatomy and Physiology, vol. xxiii., p. 523. 



