DISSECTING MANUAL. 



The dorsum is divided into anterior (oral) and posterior (phar- 

 yngeal) parts by a V-shaped groove (sulcus terminalis) whose 

 apex, directed backward, lies in a blind depression (foramen 

 caecum), and whose sides end at the anterior pillars. The an- 

 terior part is almost horizontal, forms about two-thirds of the 

 length, and usually has a median depression over the raphe; 

 the posterior part is nearly vertical and covered by lymphoid 

 follicles. The apex and part of the margin lying in front of 

 the anterior pillar are free. The inferior surface is smooth 

 and presents a mesial depression from which a fold (frenulum) 

 of mucosa passes to the floor of the mouth ; at either side are 

 two indistinct folds (plicae fimbriatse). The base is connected 

 to the mandible and hyoid bone. Filiform (conical) papilla;, 

 the smallest, cover the oral part of the dorsum and occur on 

 the upper part of the margin and tip; posteriorly they form 

 rows running outward and forward from the raphe. Fungi- 

 form papillce occur chiefly on the tip and margins, slightly on 

 the dorsum. Circumvallate papillce, the largest and fewest, 

 form a V-shaped row in front of and parallel to the "sulcus ter- 

 minalis; each presents a central cylindrical part surrounded 

 by a trench (fossa) whose outer wall is the vallum. [1000] 



Palate. The roof of the mouth consists of an anterior bony 

 part (hard palate), and a posterior part formed of soft tissues 

 (soft palate). [998] 



The soft palate is a movable fold running downward and 

 backward and ending in a conical projection (uvula), which 

 contains a prolongation of the Azygos uvulae. It consists of 

 two layers of mucous membrane enclosing the palatine mus- 

 cles, vessels, nerves, connective tissue, and glands. At each 

 side. of the uvula it has a sharp concave edge which descends 

 as a fold (posterior palatine arch) of mucous membrane cover- 

 ing the Palato-pharyngeus; another fold (anterior palatine 

 arch) descends, from just in front of the base of the uvula, 

 over the Palato-glossus. The isthmus of the fauces is the aper- 

 ture between the anterior palatine arches. [998] 



[86] 



