lie v///: MI 



of tin- Ill-ad, thinner and narrower below than above, and formed entirely of 

 fleshy Jihres which extend transversely from its anterior to its posterior 

 border. Inferiorly, it is composed of a small fasciculus, \\liicli is 

 distinguished from tho principal portion by the llightly different direction 

 of its libres, and which covers in part tho external surface of tin- muscle. 



Fig. 111. 



IIVOIDKAL AXI> J'HAKVNGKAl, UKGIONS. 



1. Xeck of inferior maxilla ; '2, Hard palaie ; :?, Molar teeth ; 4, Buccal membrane : 5, 

 Submaxillary glands; 6, Soft palate; 7, Tendon of hyoideus magnus through 

 which the tendon, 8, of the digastricus passes; 9, Lower portion of digastricus; 

 10, Stylo-hyoideus; 11, Buccal nerve; 12, Zygomatic arch ; 13, Orbital branch 

 of fifth pair of nerves ; 14, Articular process of temporal bone ; 15, Right cornu of 

 hyoidbone; 16, Hyo-glossus longus, or Kerato-glossus; 17, Lingual nerve ; 18,18, 

 Tongue ; 19, Angle of left branch of inferior maxilla ; 20, Submaxillary gland, 

 left side; 21, Subscapulo-hyoideus ; 22, Great hypoglossal nerve; 23, Hyo- 

 thyroideus ; 24, Sterno-hyoideus ; 25, Sterno-thyroideus ; 26, Subscapulo hyoi- 

 deus ; 27, Thyroid gland ; 28, External carotid artery ; 29, Pneumogastric nerve ; 

 30, Stylo-hyoideus ; 31, Genio-hyoitk-iis. 



Attachments. It originates from the mylo-hyoid line by the anterior 

 extremities of its fibres. Its movable insertion takes place on the inferior 

 face of the hy oid body, on its anterior appendix, and on a fibrous raphe which 

 extends from the free extremity of this appendix to near the genial surface, 

 and which unites, on the median line, the two mylo-hyoidc an muscles. 



Relations. By its external face, with the inferior maxilla, the digastric 

 muscle, and the Submaxillary lymphatic glands. By its internal face, with 

 the sublingual gland, tho Wharronian duct, tho hypoglossal and lingual 

 nerves, tho genio-glossus, hyo-glossus longus and brevis, and genio-hyoideus. 

 Its superior border responds to the internal pterygoid. 



Action.---T.il uniting on the median line with that of tho opposite side, 

 this muscle forms a kind of wide band or brace on which tho tongue rests. 

 When it contracts, it elevates this organ, or rather applies it against the 

 palate. 



2. Genio-hyoideus. 



Form Structure Situation. A fleshy, elongated, and fusiform body, 

 tendinous at its extremities, but especially at the inferior one, and applied, 

 T?ith its fellow of the opposite side, to the mylo-hyoidean brace. 



