|Extrinsic muscles of the tongue. Left side.|
|Gray's||subject #242 1129|
|Origin||Superior part of mental spine of mandible (symphysis menti)|
|Insertion||Dorsum of tongue and body of hyoid|
|Nerve||Hypoglossal nerve (CN XII)|
|Actions||Complex - Inferior fibers protrude the tongue, middle fibers depress the tongue, and its superior fibers draw the tip back and down|
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.
Contraction of the genioglossus stabilizes and enlarges the portion of the upper airway that is most vulnerable to collapse. 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.
Asking a patient to stick out their tongue tests the function of their hypoglossal nerve.
The name derives from Greek roots: "Geneion" for chin, and "glossa" for tongue.
- Herder et al. (2004) "Risks of general anaesthesia in people with obstructive sleep apnoea" British Medical Journal 329 (7472):955-959
- LUC geng
- SUNY Figs 34:02-01
- -227868593 at GPnotebook
- Genioglossus+muscle at eMedicine Dictionary
- Roche Lexicon - illustrated navigator, at Elsevier 25420.000-1
- Frontal section
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