In this article, we will discuss the anatomy and function of the geniohyoid muscle.
|Origin||Inferior mental spine (inferior genial tubercle)|
|Insertion||Body of the hyoid bone|
|Action||Elevates and draws hyoid bone anteriorly; shortens
the mouth floor; widens pharynx
|Innervation||Anterior ramus of spinal nerve C1 (via hypoglossal nerve)|
|Blood supply||Sublingual branch of the lingual artery|
Origin and insertion
The geniohyoid muscle originates from the inferior mental spine, located on the posterior surface of the mandible near the lower part of the mandibular symphysis. From there, the muscle fibers radiate posteroinferiorly, close to the central line and insert to the superior border of the body of the hyoid bone.
The paired geniohyoid muscles, placed next to each other, meet in the midline of the mouth floor. They lie inferior to the genioglossus muscles and right above the mylohyoid muscles.
Arterial supply of the geniohyoid muscle comes from the sublingual branch of lingual artery.
The main function of the geniohyoid muscle is to elevate the hyoid bone and draw it anteriorly. This has as a consequence the attached larynx and pharynx to move anterosuperiorly. In this way, the geniohyoid muscle participates in the deglutition (the pharynx is widened ready to receive food) and the voice production by the vocal cords.
If the hyoid muscle is fixed (by other muscles) the geniohyoid muscle assists in mouth opening by depressing the mandible and pulling it inwards. Expand your knowledge with our learning materials about the suprahyoid and other muscles of the ventral neck.