O52 THE DIGESTIVE SYSTEM. 
prominent fold, the frenulum epiglottidis or middle glosso-epiglottic fold (plica 
glosso-epiglottica media, Fig. 640), at each side of which is a wide depression, 
the vallecula. 
Two lateral glosso-epiglottic folds have been described, but these pass from the side 
of the epiglottis, not to the tongue, but upwards along the wall of the pharynx, upon 
which they are soon lost ; consequently the term pharyngo-epiglottic is more applicable 
to them. 
The anterior or oral portion of the dorsum lingue, namely, the part in front 
of the suleus terminalis (Fig. 640), is convex, both from before backwards and 
Internal jugular vein Hypoglossal nerve 
Spinal accessory nerve | Internal carotid artery 
ivastrie sc]e | | A 
Digastric muscle Pneumogastric nerve 
| Sympathetic 
Ascending pharyngeal artery 
Odontoid process 
Stylohyoid 
Glosso- ly : 
pharyngeal nerve~\_ | Ss 
Parotid gland—t_ f-= 
Temporo- 
maxillary vein~ 
Post-pharyngeal 
) _--~ lymphatic eland 
External carotid | 
artery ij i aS “Qe oa7 => LA IE, Superior 
Styloglossus +t 4 : Is - (FJ constrictor muscle 
SUS iim ace SX pan ae EX 
Ascending y 
palatine artery 
_Posterior palatine 
a arch 
oe 
i | y ¢ ) ‘ + Tonsil 
Internal pterygoid - \ y =~ eo 
Pharyngo-epiglottie 
Epiglottis “fold 
Frenulum \ \ 
epiglottidis \ 
Masseter —\—, 
Anterior palatine 
arch 
Circumvallate 
F ya pillee 
Pharyngeal portion —— Pal 
ot tongue 
L Raphe of tongue 
Conical papille 
Fungiform papilla 
Buccinator 
Fungiform papilla 
Fic. 640.—HOoRIZONTAL SECTION THROUGH MouTH AND PHARYNX AT THE LEVEL OF THE TONSILS. 
The stylopharyngeus, which is shown immediately to the inner side of the external carotid artery, and the 
prevertebral muscles, are not indicated by reference lines. 
from side to side in the resting condition of the organ (Fig. 637). It usually 
presents also a sheht median depression, along the centre of which may be seen 
some indication of a median raphe in the form of an irregular crease, which ends 
posteriorly near the foramen cecum. The mucous membrane of this portion of 
the dorsum is thickly covered with the prominent and numerous papille (papille 
linguales) which give the tongue its most characteristic appearance. 
On the pharyngeal part of the tongue there are also small papillary projections of the 
corium, but the epithelium fills up all the intervals between the papille, and, as it were, levels 
off the surface, so that none are visible to the eye as projections above the general level. Over 
the anterior part of the tongue, on the contrary, the projections of the corium are large and. 
prominent, and the intervals between them, while they are covered, yet are not filled up, by the 
epithelium, so that the projections stand out distinctly and independently, and in places attain a 
height of nearly 2 mm. above the general surface. 
