Geniohyoid muscle

Geniohyoid muscle
Anterior view. Geniohyoid muscle labeled at upper center left
Extrinsic muscles of the tongue. Left side.
Latin	musculus geniohyoideus
Gray's	subject #112 393
Origin	Symphysis menti
Insertion	hyoid bone
Artery
Nerve	C1 via the hypoglossal nerve (XII)
Actions	carry hyoid bone and the tongue upward during deglutition

The Geniohyoid muscle is a narrow 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") to the hyoid bone.

Origin and insertion

It arises from the inferior mental spine, on the back of the symphysis menti, 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 fellow of the opposite side. It thus belongs to the suprahyoid muscles. The nerve supply to geniohyoid is from C1 running with the hypoglossal nerve.

Action

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

Innervation

It is innervated by fibers from C1 hitchhiking on Cranial Nerve XII.

Variations

It may be blended with the one on opposite side or double; slips to greater cornu of hyoid bone and Genioglossus occur.

Additional images

• 

  Hyoid bone. Anterior surface. Enlarged.

• 

  Sagittal section of nose mouth, pharynx, and larynx.

External links

• LUC genh
• -221249457 at GPnotebook
• SUNY Figs 34:02-06
• Geniohyoid+muscle at eMedicine Dictionary
• Roche Lexicon - illustrated navigator, at Elsevier 25420.000-1
• Frontal section

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.