MUSCLES OF THE TONGUE, 



285 



peculiar to itself— the intrinsic muscles, which will be noticed along 

 with the tongue ; and partly of muscles arising from neighbouring 

 parts — the extrinsic muscles about to be described. 



The genio-glossus or genio-hyo-glossiis muscle is fan-shaped, and 

 is placed vertically in contact with its fellow in the mesial plane. It 

 arises by a short tendon from the superior genial tubercle behind the 

 symphysis of the jaw : from this its fibres diverge, to be inserted, the 

 inferior, for the most part, into the body of the hyoid bone, and a 

 few into the side of the pharynx ; the superior into the tip of the 

 tongue ; and the intermediate fibres into the whole length of the 

 tongue spreading outwards in its substance. 



jRdations. — The external surface is in contact with the lingualis inferior, hyo- 

 glossus and stylo-glossus muscles, the sublingual gland, the ranine vessels, and 

 the nei-ves of the tongue, and its lower border with the genio-hjoid muscle. 



Varieties. — Occasional slips of this muscle have been noticed passing to the 

 epiglottis (Luschka), or to the pharynx (Win8low),or to the stylo-hyoid ligament 

 (Sommerring). It has also been found united anteriorly with the genio-hyoid 

 muscle. 



The hyo-glossns is a flat quadrate muscle, arising from the whole 

 length of the great cornu, from the lateral part of the body, and from 



Fig. 211. — Deep Muscles of the Fig. 211. 



Cheek, Pharynx, &c. (modified 

 from Cloquet). (A. T. ) ^ 



The pharynx has been distended 

 by stuffing. «, external pterygoid 

 process ; b, styloid process, with 

 short portions of the three styloid 

 muscles attached ; c, body of the 

 lower jaw, which has been divided 

 at the place where the pterygo- 

 maxillary ligament + is attached ; 

 d, body of the hyoid bone ; e, 

 thyroid cartilage ; /, cricoid carti- 

 lage ; g, trachea ; 1, outer part of 

 the orbicularis oris muscle ; 2, buc- 

 cinator ; 3, superior constrictor of 

 the pharynx ; 4, middle constrictor ; 

 5, inferior constrictor ; 6, ceso- 

 j)hagus ; 7, points by three lines to 

 the lower parts of the stylo-glossus, 

 stylo-hyoid, and stylo-pbaryngeus 

 muscles respectively ; 8, mylo- 

 hyoid ; 9, hyo-glossus, of which a 

 small part is removed posteriorly to 

 show the attachment of the middle 

 constrictor ; 10, thyro-hyoid. 



the small cornu of the hyoid 

 bone ; it passes upwards to be 

 inserted into the side of the 

 tongue, blending with the 

 stylo-glossus and palato- 

 glossus muscles. 



Eelat'wns. — The hyo-gloseus is concealed by the digastric, stylo-hyoid and 

 mylo-hyoid muscles, except at its posterior inferior angle : the deep part of the 

 submaxillary gland rests on its surface, and it is crossed from below upwards by 



