142 A MANUAL OF ANATOMY. 



The cartilage which constitutes the anterior portion of 

 the Eustachian tube forms a prominent ring around the 

 opening orifice called the tubal eminence. 



Behind the Eustachian tube opening is a blind pit, the 

 fossa of Rosenmuller. 



Below the posterior nares the soft palate hangs down- 

 ward and terminates medianly in the uvula. The soft 

 palate serves to shut off the nasal passages from the 

 pharynx in deglutition. 



Laterally the free margin of the soft palate is thrown 

 into two prominent arches ; the posterior, descending to 

 the pharyngeal wall ; the anterior, to the side of the tongue, 

 leaving a hollow between them. These arches are called 

 the anterior and posterior arches of the fauces, or 

 the anterior and posterior palatine arches. The depres- 

 sion between them is the tonsillar recess, and lodges the 

 tonsil. 



The posterior arch is produced by the palatopharyngeus, 

 the anterior by the palatoglossus muscle. 



The tonsils are two oval-shaped masses of spongy ade- 

 noid tissue, situated within the two palatine arches. Their 

 size in the cadaver is never as large as in the living, conse- 

 quently their relative size can best be estimated from an 

 examination of the throats of friends. 



The roof of the pharynx is occupied by an adenoid mass, 

 the pharyngeal tonsil, which in children sometimes 

 assumes very large proportions. 



The base of the tongue is seen below the soft palate. 

 The opening of the mouth posteriorly into the pharynx is 

 called the isthmus faucium. It is bounded by the soft 

 palate above, the faucial arches and tonsils laterally, and 

 the base of the tongue below. Upon the base of the 

 tongue will be seen in the middle line the foramen caecum, 



