THS MOUTH. 



311 



posterior border circumscribes tie orifice wbich establkLB, „ 



tion between these two cavities. establishes a communica- 



• This partition, which continues the palate posteriorly, represents in it« 

 external form a membranes valve, oblique from above t^o below and befor^ 



, ^■^^%7f™';f ""'^^'-/r^' t"™ed towards the mouth, shows loud 

 udmal folds and transverse ridges, with multitudes of orifice; belon.S^o 

 the submucous glandule. On its sides it is united to the base of the tongue 

 by means of two thick mucous columns, designated the posterior pXs 

 of the tongue. The supenorov posterior face constitutes the anterior wall 

 Of the pharynx ; it only exhibits some very slight longitudinal ridges 



Fig. 152. 



MEDIAN LONOITUDINAL SECTION OF THE HEAD AND UPPER PART OF NECK. 



1, Upper lip ; 2, Premaxilla ; 3, Hard palate ; 4, Tongue ; 5, Septum nasi ; 6, Nasal 

 bone; 7, Palatine arch; 9, Pterygoid bone ; 10, Epiglottis ; 11, Entrance to the 

 Enstachian tube; 12, Arytenoid cartilage, 13, Cricoid cartilage; 14, (Esophagus; 

 15, Frontal bone and sinus ; 16, Cerebrum ; 17, Corpus callosura ; 18, Cerebellum ; 

 19, Sphenoid bone ; 20, Medulla oblongata ; 21, Cervical ligament ; 22, Spinal 

 cord ; 23, Occipital bone ; 24, 24, Atlas ; 25, 25, Dentata ; 26, Trachea. 



The two lateral horders are inserted into the walls of the two cavities 

 wMch the soft palate separates. The anterior border, continuous with the 

 palate, is attached to the palatine arch, and follows the curve described by 

 it. The posterior border, the only free one, has a concave form, and 

 closely embraces the base of the epiglottis, which is most usually found 

 reversed on the posterior surface of this curtain. This border is continued 

 at its extremites by two thin prolongations, which can be followed on the 

 lateral walls of the pharynx to the oesophageal infundibulum, above which 

 they unite in the form of an arch. These prolongments are named the 

 posterior pillars of the soft palate, in contradistinction to the two mucous 

 folds at the base of the tongue, which constitute, by their relation to this 

 partition, veritable anterior pillars. This posterior border concurs to cir- 

 25 



