PALATO-GLOSSUS PALATO-PHARYNGEUS. 195 



This muscle must be turned down from -pig. 112.* 



its origin on one side, and removed, and the 

 superior constrictor dissected away from its 

 pterygoid origin, to bring the next muscle 

 into view. 



The TENSOR PALATI (circumflexus) is a 

 slender and flattened muscle ; it arises from 

 the scaphoid fossa at the base of the inter- 

 nal pterygoid plate and from the anterior 

 aspect of the Eustachiari tube. It descends 

 to the hamular process, around which it 

 turns and expands into a tendinous aponeu- 

 rosis, which is inserted into the transverse 

 ridge on the horizontal portion of the palate bone, and into the raphe. 



Relations. By its external surface with the internal pterygoid muscle ; 

 by its internal surface with the levator palati, internal pterygoid plate, 

 and superior constrictor. In the soft palate, its tendinous expansion is 

 placed in front of the other muscles and in contact with the mucous mem- 

 brane. 



The AZYGOS UVULAE is not a single muscle, as might be inferred from 

 its name, but a pair of small muscles placed side by side in the middle 

 line of the soft palate. They arise from the spine of the palate bone, and 

 are inserted into the uvula. By their anterior surface they are connected 

 with the tendinous expansion of the levatores palati, and by the posterior 

 with the mucous membrane. 



The two next muscles are brought into view throughout the whole of 

 their extent, by raising the mucous membrane from off the pillars of the 

 soft palate at each side. 



The PALATO-GLOSSUS (constrictor isthmi faucium) is a small fasciculus 

 of fibres that arises in the soft palate, and descends to be inserted into the 

 side of the tongue. It is the projection of this small muscle, covered by 

 mucous membrane, that forms the anterior pillar of the soft palate. It has 

 been named constrictor isthmi faucium from a function it performs in 

 common with the palato-pharyngeus, viz. of constricting the opening of 

 the fauces. 



The PALATO-PHARYNGEUS forms the posterior pillar of the fauces ; it 

 arises by an expanded fasciculus from the lower part of the soft palate, 

 where its fibres are continuous with those of the muscle of the opposite 



* The muscles of the soft palate. 1. A transverse section through the middle of the 

 base of the skull, dividing the basilar process of the occipital bone in the middle line, 

 and the petrous portion of the temporal bone at each side. 2. The vomer covered by 

 mucous membrane and separating the two posterior nares. 3, 3. The Eustachian tubes. 

 4. The levator palati muscle of the left side; the right has been removed. 5. The ha- 

 mular process of the internal pterygoid plate of the left side, around which the aponeu- 

 rosis of the tensor palati is seen turning. 6. The pterygo-maxillary ligament. 7. The 

 superior constrictor muscle of the left side, turned aside. 8. The azygos uvulae muscle. 

 9. The internal pterygoid plate. 10. The external pterygoid plate. 11. The tensor pa- 

 lati muscle. 12. Its aponeurosis expanding in the structure of the soft palate. 13. The 

 external pterygoid muscle. 14. The attachments of two pairs of muscles cut short; the 

 superior pair belong to the genio-hyo-glossi muscles ; the inferior pair to the genio- 

 hyoidei. 15. The attachment of the rnylo-hyoideus of one side and part of the opposite. 

 16. The anterior attachments of the digastric muscles. 17. The depression on the lower 

 jaw corresponding with the submaxillary gland. The depression above the mylo-hyri 

 deus, on which the number 15 rests, corresponds with the situation of the sublinguaJ 

 gland. 



