550 . AX ATOMY IX A XUTSHELL. 



has a ventral ridge in its center. There is a small tubercle on the upper end of 

 this ridge. This surface has attached to it the following muscles: Genio- 

 hyoid. Genio-hyo-glossus, Hyo-glossus, Mylo-hyoid, Stylo-hyoid, the aponeu- 

 rosis of the Digastric muscle. 



The posterior surface of the hotly is concave. 



The lateral surfaces articulate with the greater cornua. 



The superior surface gives attachment to the Genio-hyo-glossus, and 

 ( Jhondro-glossus. 



The inferior border gives attachment to the Sterno-hyoid, Omo-hyoid, and 

 Thyro-hyoid muscles. All muscles attached to this hone are in pairs. 



The greater cornu projects backward and outward from the lateral sur- 

 face of the body. The thyro-hyoid ligament is attached to the end of the 

 greater cornu. The Hyo-glossus muscle is attached to its outer surface, the 

 Middle consl rictor to its upper border, and the Thyro-hyoid to its lower border. 



The lesser cornu is situated at the angle where the greater cornu joins the 

 hotly. The stylo-hyoid ligament is attached to its apex. This articulation 

 may he ankylosed hut is generally free. 



Ossification. — From five centers. 



Articulation. — It articulates with no bone. 



A it \i hment of Muscles. — This bone has twelve pairs of muscles attached 

 to it, as well as the thyro-hyoid membrane and the stylo-hyoid, thyro-hyoid, 

 and hyo-epiglottic ligaments. 



Blood Supply. — Superior thyroid and lingual of the external carotid 

 artery. 



1. Sterno-hyoid muscle, which has been described on page 40. 



2. Thyro-hyoid. — 



Origix. — From the oblique line on the thyroid cartilage. 



Insertion.- Into the body and the greater cornu of the hyoid bone. 



Action. — To depress the larynx and the hyoid hone. 



Nerve Supply. — Hypoglossal nerve. 



Blood Supply. — Superior thyroid artery. 



'■'•. Omo-hyoid muscle, which has been described on page 59. 



4. Digastric muscle, which has been described on page 521. 



5. Stylo-hyoid, which has been described 522. 



6. Mylo-hyoid, which has been described on page 544. 



7. Genio-hyoid, which has been described on page 544. 



8. Genio-hyo-glossus, which has been described on page 544. 



o. Chondro-glossus.- Description.— This muscle is sometimes described 

 as pari of the Hyo-glossus. 



Origin. From the body and lesser cornu of the hyoid bone. 



Insertion. Ento the intrinsic muscles of the tongue between the Hyo- 

 glossus ami the Genio-hyo-glossus. 



Action. To draw down tin- side of the tongue. 



\i.i;\ e Supplj .- -Hypoglossal. 



I'.i.t k >n Si ppl"5 . Lingua] artery. 



Hi. Byo-glossus. 



