Genioglossus

The genioglossus is a muscle of the human body which runs from the chin to the tongue.

Structure
Genioglossus is the fan-shaped extrinsic tongue muscle that forms the majority of the body of the tongue. Its origin is the mental spine of the mandible and its insertions are the hyoid bone and the dorsum of the tongue. Innervated by the hypoglossal nerve (CN XII), it depresses and protrudes the tongue.

Clinical relevance
A relaxation of the genioglossus and geniohyoideus muscles, especially during REM sleep, is implicated in Obstructive Sleep Apnea (OSA.)

Peripheral damage to the hypoglossal nerve can result in deviation of the tongue to the damaged side.

Etymology
The name derives from Greek roots: "Geneion" for chin, and "glossa" for tongue.