TONGUE 



233 



ive tissue. Some of these striated fibers are branched. The muscula- 

 ture of the tongue is partly divided into right and left halves by a 

 dense median connective tissue partition, the septum lingua, which begins 

 low on the hyoid bone, attains its greatest height in the middle of the 

 tongue, and becomes lower anteriorly until it disappears. It does not 

 extend clear through the tongue since it ends 3 mm. beneath the dorsum. 

 The muscles of the tongue are partly vertical (Mm. genioglossus, hyo- 

 glossus, and verticalis lingua}, partly longitudinal (Mm. styloglossus, 

 chondroglossus, superior and inferior longitudinalis lingua} and partly 



Tuica propna. 



Secondary papillae. Taste bud. 

 Vallate papilla. 

 \ 



Groo 



Orifice 



of a Small 



serous papilla, 

 gland. 



Epithelium. 



Tunica 

 propria 



Striated 

 muscle. 



Muscle fibers in cross Nerye with Fascia Mucous Vein. 



and longitudinal section. ganglion cells, linguae. gland. 



FIG. 223. VERTICAL SECTION OF A HUMAN VALLATE PAPILLA. X 25. 



transverse (M. transversus lingua). The glossopalatine muscle of the 

 palatine group also enters the tongue. Some of the muscle fibers are ob- 

 lique but many of the bundles cross at right angles. In the connective 

 tissue between them, medullated nerves are abundant. Some are sensory 

 nerves to the mucosa, but many of them are the lingual branches of the 

 hypoglossal nerve which supply all the tongue muscles except the inferior 

 longitudinal; the latter is supplied by fibers from the chorda tympani 

 Sensory spindles have been found in the lingual muscles. 



Blood vessels are numerous in the submucosa and form extensive 

 capillary networks in the tunica propria of both primary and secondary 



