314 HEALTH AND DISEASE 



Insertion. The second belly is inserted into the posterior border of the 

 lower jaw behind the chin. 



Action. To raise the hyoid bone and assist in opening the mouth. 



OccipitO-Styloid. A very short, small, flat muscle situated at the 

 posterior part of the base of the skull. 



Origin. From the anterior part of the styloid process of the occipital 

 bone. 



Insertion. Into the upper extremity of the long cornu of the hyoid 

 bone (bone of the tongue). 



Action. To draw the bone of the tongue upwards and backwards. 



MUSCLES OF THE TONGUE 



Stylo-GloSSUS. A long, narrow, flat muscle situated on the side of 

 the tongue. 



Origin. From the outer part of the inferior extremity of the long 

 cornu of the tongue bone. 



Insertion. Into the tip of the tongue. 



Action. Acting with its fellow on the opposite side, it would pull 

 the tip of the tongue upwards. Acting alone, it would draw it to one 

 side. 



Great Hyo-GlossUS. Situated in the substance of the tongue. 



Origin. From the heel-like process and body of the tongue bone. 



Insertion. Into the front part of the mucous membrane of the tongue 

 along the greater portion of its length. 



Action. To draw the tongue backwards and upwards. 



Genio-HyO-GloSSUS. A broad, thin, fan-shaped muscle placed in the 

 centre of the tongue. Some of its fibres pass downwards to the tip, others 

 to the centre, and a third portion to the root of the tongue. 



Origin. From the inner surface of the lower jaw, near the symphysis, 

 or union of the two branches. 



Insertion. Into the under surface of the mucous membrane, along its 

 middle, from the tip to the root. 



Action. The lower portion of the muscle when contracting would draw 

 the tongue into the mouth, the upper division would cause it to protrude. 

 The central part would pull it away from the roof. 



Small Hyo-GloSSUS. A very small muscle surrounded by fat and 

 situated at the root of the tongue. 



Origin. From the inferior extremity of the small cornu and the body 

 of the tongue bone. 



Insertion. Into the posterior part of the substance of the tongue. 



