MUSCULAR SYSTEM. 97 



nally, with the larynx, os hyoides, and submaxillary gland : infe- 

 riorly, with the submaxillary vessels and the skin. 



Direction. — Oblique : from behind, forwards and downwards ; 

 from before, upwards and backwards. 



Structure. — It consists of two fleshy bellies united by an inter- 

 mediate tendon, which passes and plays through a sort of pulley 

 formed by the tendon of the hyoideus. 



Action. — Not very apparent; implicated, seemingly, with that 

 of the hyoideus. 



MYLO-HYOIDEUS. 



Situation. — Spreading along the side of the jaw. 



Figure. — Broad, thin, half-penniform. 



Attachment . — Outwardly, to the roots of the alveolar processes 

 and the side of the jaw, extending forwards to the symphysis: 

 inwardly, to the body of the os hyoides. 



Relation. — Outwardly, with the jaw; inwardly, with the sub- 

 lingual gland, genio-hyoideus, and gustatory and ninth pair of 

 nerves. 



Direction. — Oblique: from above downwards, inclining out- 

 wards. 



Structure. — Fleshy: united to its fellow (of the opposite side) 

 through the medium of a tendinous line, which extends from the 

 end of the spur process of the os hyoides to the symphysis of the 

 jaw„ 



Action.— To draw the os hyoides forwards and upwards; and, 

 thereby, raise the tongue within the mouth. 



GENIO-HYOIDEUS. 



Situation. — Above the preceding muscle. 



Figure. — Half-penniform: extremities, narrow; middle part, 

 broad. 



Attachment. — Anteriorly, to the jaw, near the symphysis; pos- 

 teriorly, to the spur process of the os hyoides. 



Relation. — Inferiorly and externally, with the mylo-hyoideus ; 

 superiorly, with the genio-hyo-glossus ; internally, with its fellow. 



Direction. — Oblique : from before, backwards ; and from with- 

 out, inwards. 



Structure. — Tendinous at the extremities : intermediate part, 

 fleshy. 



HYOIDEUS MAGNUS. — Kerato-tiyoideus Magnus. 

 Situation. — Antero-superior part of the neck. 

 Form. — Fusiform : flattened upon its sides. 

 Attachment. — Posteriorly, to the postero-inferior part or angle 

 of the corner of the os hyoides ; anteriorly, to a little tubercle 



