Kit;:; 



rated in its anterior two-thirds from the inferior surface l>y tho lateral margins 



and apex. A muscular body is attached posteriorly and interiorly at the root. 



The dorsum dig. 7.V.M is marked in its anterior two-thirds by a slight longitudinal 

 groove, t he median sulcus, and just beyond the dorsal end of t his 1 here is usually a 

 small blind pouch, the foramen caecum (Moniagni). which represents the superior end 

 of the thyreo-glossal duel. Two sli.irht grooves run Yentrally and laterally from the 

 foramen cnrum. and together form a V-shaped groove, the terminal sulcus, which 

 marks the point of union of the body of the tongue, derived from the tubercnlum 

 impar. and the root , derived from t he anterior ends of the second and third branchial 

 arches. It also marks a division of the dorsutn into a ventral or oral portion and a 

 dorsal or pharyngi-.-d part . 



The mucous membrane covers the whole of the free surface of the tongue (fig. 

 7.")!)). Dorsally. in the middle line, is the prominent median glosso-epiglottic 

 fold, and on each side of this the more rounded lateral glosso-epiglottic folds, 

 connecting the tongue and the epiglottis. Between the median and lateral fold on 

 each side there is a .shallow fossa, the epiglottic vallecula. Laterally the mucous 



FlG. 760. Sri-KKioii Si i;i \ mi: TONGI i. i Mmliiird from Spnlteholz.) 



INFERIOR SURFACE 

 LATERAL MARGIN 



FIMBRIATE FOLDS 

 Ranine vein 

 FRENULUM 



SU8LIN6UAL FOLD 

 SUBLIN8UAL CARUNCLE 



membrane of the dorsal portion is reflected over the tonsil and palatine arches, and 

 ventrally it is reflected over t he lateral margins and apex to the inferior surface, from 

 which it passes to the floor of the mouth and thence to the gums of the lower jaw. 



I'pon the inferior surface of the tongue, near the tip. is a median depression 

 (fig. 760), from which a prominent median fold of mucous membrane, the frenulum, 

 stretches to the gums. On each side of the frenulum, and close to it, at about the 

 junction of the inferior surface of the tongue and the floor of the mouth, is a rounded 

 nodule, the sublingual caruncle, upon which the submaxillary duct opens. 

 Running dorsally and laterally from each caruncle is a long, rounded ridge, the sub- 

 lingual fold, beneath which is situated the sublingual gland, and about midway be- 

 tween the frenulum and the lateral margins of the tongue are two rasrged folds of 

 mucous membrane, the fimbriate folds, which converge ventrally. Between these 

 folds and the frenulum the ranine veins are seen beneath the mucous membrane. 



Papillae of the tongue. Over the oral portion of the dorsum of the tongue the 

 red mucous membrane is somewhat whitened by the thickening of the epithelium, 

 which produces the numerous lingual papillae (fig. 759). Four kinds can be dis- 



