THE LINGUAL REGION. 



415 



4. Lingual Region. 



Genio-hyo-glossus. Stylo-glossus. 



Hyo-glossus. Palato-glossus. 



Chondro-glossus. 



Dissection. After completing the dissection of the preceding muscles, saw through the 

 lower jaw just external to the symphysis. Then draw the tongue forward, and attach it, by a 

 stitch, to the nose ; when its muscles, which are thus put on the stretch, may be examined. 



The Genio-hyo-glossus has received its name from its triple attachment to the 

 jaw. hyoid bone, and tongue, but it would be better named the Grenio-glossu*, 



FIG. 278. Muscles of the tongues Left side. 



since its attachment to the hyoid bone is verj,slight or altogether absenf. It is a 

 flat, triangular muscle, placed vertically on 'either side of the middle line, its apex 

 corresponding with its point of attachment to the lower jaw, its base with its 

 insertion into the tongue and hyoid bone. It arises by a short tendon from the 

 superior genial tubercle on the inner side of the symphysis of the jaw, immediately 

 above the Genio-hyoid ; from this point the muscle spreads out in a fan-like form, 

 a few of the inferior fibres passing downward, to be attached by a thin aponeurosis 

 into the upper part of the body of the hyoid bone ; the middle fibres passing back- 

 ward, and the superior ones upward and forward, to enter the whole length of the 

 under surface of the tongue, from the base to the apex. The two muscles lie on 

 either side of the median plane ; behind, thev are quite distinct from ea.ch other, 

 and are separated at their insertion into the under surface of the tongue oy a ten- 

 dinous raphe, which extends through the middle of the organ ; in front, the two 

 muscles are more or less blended : distinct fasciculi are to be seen passing off from 

 one muscle, crossing the middle line, and intersecting with bundles of fibres 

 derived from the muscle on the other side (Fig. 279). 



Relations. By its internal surface it is in contact with its fellow of the opposite 



