The geniohyoid muscle is a narrow paired muscle situated superior to the medial border of the mylohyoid muscle. It is named for its passage from the chin ("genio-" is a standard prefix for "chin")
Structure
The geniohyoid is a paired short muscle that arises from the inferior
mental spine, on the back of the mandibular symphysis, and runs backward and slightly downward, to be inserted into the anterior surface of the body of the
hyoid bone.
It lies in contact with its counterpart on the opposite side. It thus belongs to the suprahyoid muscles. The muscle receives its blood supply from branches of the
lingual artery.
Innervation
The geniohyoid muscle is innervated by fibres from the first cervical spinal nerve travelling alongside the hypoglossal nerve.
Although the first three cervical nerves give rise to the
ansa cervicalis, the geniohyoid muscle is said to be innervated by the first cervical nerve, as some of its efferent fibers do not contribute to ansa cervicalis.
Variations
It may be blended with the one on opposite side or double; slips to
greater cornu of hyoid bone and
genioglossus occur.
Function
The geniohyoid muscle brings the
hyoid bone forward and upwards.
This dilates the
larynx, assisting respiration.
During the first act of
deglutition, when the mass of food is being driven from the mouth into the pharynx, the hyoid bone, and with it the tongue, is carried upward and forward by the anterior bellies of the Digastrici, the Mylohyoidei, and Geniohyoidei. It also assists in depressing the mandible.
[
]
History
The inclined position of the geniohyoid muscle has been contrasted to the horizontal position in .
==Additional images==
See also
External links
