THE TONGUE. 



1125 



in its whole extent ; the base, the posterior wide end which is attached to the hyoid 

 bone ; the apex linguae, the pointed and free anterior extremity ; the margo 

 lateralis, which is free in 'its anterior half or more, i.e. in front of the attach- 

 ment of the anterior palatine arch (Fig. 890). Finally, the unattached portion 

 on the inferior aspect, seen when the apex is turned strongly upwards (Fig. 892), 

 constitutes the facies inferior, or inferior surface ; whilst the thick posterior portion, 

 fixed by muscles and mucous membrane to the hyoid bone and mandible, is known 

 as the radix linguae or root. 



The dorsum of the tongue, when the organ is at rest, is strongly arched 

 antero-posteriorly in its whole length (Fig. 889), the greatest convexity correspond- 

 ing to the attachment of the glosso-palatine arch. When removed from the body 





Internal jugular vein 

 Accessory nervt 

 Digastric muscle 



Hypoglossal nerve 

 Into 



ternal carotid artery 

 Vagus nerve 



Sympathetic trunk 



Ascending pharyngeal artery 



iraiutj 



Posterii 

 External 



Stylo-hyoid 

 Glosso- 



pharyngeal nerve 

 Parotid gland 

 terior facial 

 vein 



,1 carotid 



artery 



Styloglossus 



Ascending 



palatine artery 



Internal pterygoid 

 Epiglottis 



Olosso-epiglottic 

 fold 



Masseter- 



ryngeal portion 

 of tongue 



Dens 



m 



Fungiform papilla 

 Buccinator 



Retro-phary n geal 

 lymph gland 



Superior 

 constrictor muscle 



Pharyngo-palatine 

 arch 



Palatine tonsil 



Pharyngo-epiglottic 

 fold 



Glosso-palatine 

 arch 



Vallate papillae 



Raphe of tongue 



Conical papilla 



Fungiform papilla 



FIG. 890. HORIZONTAL SECTION THROUGH MOUTH AND PHARYNX AT THE LEVEL OF THE PALATINE TONSILS. 



The stylopharyngeus muscle, which is shown immediately to the medial side of the external carotid artery, and 

 the prevertebral muscles, are not indicated by reference lines. 



the tongue, unless previously hardened in situ, loses its natural shape, and 

 appears as a flat, elongated oval structure, which gives a very erroneous idea of its 

 true form and connexions. 



Both in structure and in function, as well as in embryological history, the 

 dorsum linguae is divisible into two areas an anterior or oral part, which 

 lies nearly horizontally on the floor of the mouth, and constitutes about two-thirds 

 of the length of the whole tongue (Fig. 890) ; and a posterior or pliaryngeal part, 

 the remaining third of the organ, which is placed nearly vertically, and forms the 

 anterior wall of the oral pharynx (Fig. 889). The separation between these two 

 parts, which differ in appearance as well as in direction, is indicated by a distinct 

 V-shaped groove, called the sulcus terminalis (Fig. 890), the apex of which is 



