Hand atlas of human anatomy - EducationNest

40 Bones of the Skiill.
Corpus
Cornu majus
Cornu minus
Corpus
51 and 52. Hyoid bone, os hyoideum.
From above. Right half, from the left.
The OS hjoidenm (hyoid bone) lies as an unpaired, horse-slioe-shaped bone behind
and below the Ljwer jaw between the muscles, without direct connection with the other bones.
It is divisible mto a middle i)icc(^ or corpus, two cornua majora and two cornua minora.
The corpus (body) is a transversely placed oblong plate with an anterior surface, bent
so as to be cunY(^x in front and above, and a concave posterior surface. The anterior surface
presents variably developed ridges for the muscular attachments, the posterior is smooth. At
the lateral ends are small fnssae, below for union mth the cornua majora, aliove for the
cornua minora.
The cornna majora are thin, laterally Huttened plates of bone, longer than the body.
They are placi'd horizontally or directed obliquely upward, are united in front with the body
l)y means of a narrow plate of cartilage or by a small joint with a joint cavity and a tight
capsule. Behind, each ends in a small button-like projection.
The cornua minora are small pieces, sometimes reniainmg cartilaginous, which are
attached abo\e near the point of union of the body and the cornua majora. either by means
of a small jotut with joint cavity and loose capsule or by ligamentous vmion only. They are
surrounded by the end of the Kgamentum stylohoideum (see Kg. 555), a thui round elastic
fibrous ligament which extends ft-om the processus styloideus oss. temjior, int«rwoven in the
deep layer of the cervical fascia. Sometmies it contains masses of lume, the single pieces
liring more or li.^ss se]):irated from one another. The processus styl.jiileus, tlie lig. stylo-
hoideum and the cornu minus oss. liyoid. arise fi-om the second branchial arch of the foetus.