THE TONGUE 



1107 



The free inferior surface of the tongue (fig. 858) is covered by a thin smooth 

 mucosa. In the median line is a prominent fold, the frenulum, which connects 

 the tongue with the mandible and the floor of the mouth. On each side of the 

 inferior surface, an irregular, variable, fringed fold, the plica fimbriata, extends 

 from near the apex backward approximately parallel with the lateral margm of 

 the tongue (fig. 858) . Between the frenulum and the plicae fimbriatse, the Ungual 

 (ranine) veins are visible on each side beneath the mucosa. 



The root (or base) of the tongue [radix linguae] belongs to the pharynx, but is 

 here included with the mouth for convenience of description. Its free surface is 

 directed posteriorly, and represents the continuation of the dorsum linguae (fig. 

 854). Laterally it is continuous with the region of the palatine tonsils. Infe- 



FiG. 854. — Dorsum and Root of the Tongue. (Papillae diagrammatic.) 



Ventricular fold Lower part of pharynx 



Extremity of cornu of 

 hyoid bone 



Superior cornu of 

 thyreoid cartilage 



Lateral glosso- 

 epiglottidean fold 



Anterior wall of the 

 pharynx 



Cornicular tubercle 



Cuneiform tubercle 

 Recessus piriformis 



Vocal fold (true vocal 

 cord) 



Epiglottis 



Median glosso- 

 epiglottidean fold 



Pharyngopalatine 



Glossopalati: 



Vallate (circumvallate) 



Fungiform papillae 



riorly it extends to the epiglottis, with which it is connected by a median and two 

 lateral folds, between which are the depressions known as the valleculcB. The 

 mucosa over the root of the tongue is irregular and warty in appearance due to 

 the projections of the underlying nodular masses of lymphoid tissue, the lingual 

 follicles. A crypt or tubular pocket of surface epithelium usually dips down into 

 each of these follicles, as seen in surface view (fig. 854), and shown in section (fig. 

 859). The follicles vary from 34 to 102 in number, the average being 66 (Ostman), 

 and are somewhat irregular in size and form. They are often arranged in more or 

 less distinct longitudinal rows, with corresponding folds of the mucosa (Jurisch). 

 The lingual follicles are collectively designated as the lingual tonsil [tonsilla 

 linguae]. Between the Ungual follicles and around the periphery of the lingual 

 tonsil there are found smaller ordinary nodules (without crypts) and indefinite 



