Extrinsic muscles of the tongue. Left side.
|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|
|Anatomical terms of muscle|
Genioglossus is the fan-shaped extrinsic tongue muscle that forms the majority of the body of the tongue. Its arises from the mental spine of the mandible and its insertions are the hyoid bone and the bottom of the tongue.
The canine genioglossus muscle has been divided into horizontal and oblique compartments.
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 
Peripheral damage to the hypoglossal nerve can result in deviation of the tongue to the damaged side. The genioglossus is often used as a proxy to test the function of the hypoglossal nerve, by asking a patient to stick out their tongue.:992
- Singh, Inderbir (2009). Essentials of anatomy (2nd ed. ed.). New Delhi: Jaypee Bros. ISBN 978-81-8448-461-8.
- Drake, Richard L.; Vogl, Wayne; Tibbitts, Adam W.M. Mitchell ; illustrations by Richard; Richardson, Paul (2005). Gray's anatomy for students (Pbk. ed.). Philadelphia: Elsevier/Churchill Livingstone. ISBN 978-0-443-06612-2.
- Mu, L; Sanders, I (Nov 1, 2000). "Neuromuscular specializations of the pharyngeal dilator muscles: II. Compartmentalization of the canine genioglossus muscle.". The Anatomical record 260 (3): 308–25. PMID 11066041.
- Herder et al. (2004) "Risks of general anaesthesia in people with obstructive sleep apnoea" British Medical Journal 329 (7472):955-959
- Origin, insertion and nerve supply of the muscle at Loyola University Chicago Stritch School of Medicine
- SUNY Figs 34:02-01
- -227868593 at GPnotebook
- Genioglossus+muscle at eMedicine Dictionary
- Anatomy diagram: 25420.000-1 at Roche Lexicon - illustrated navigator, Elsevier
- Frontal sectionGalea aponeurotica
Musclesof head and neck: the head(TA A04.1, GA 4.378)Masseteric fasciaTemporal fasciaDeep portion: cementomaxillary tendonSuperficial portion: cementomandibular tendon Extraocular (CN III, IV, VI) Mastication (CN V3) fascia: Facial (CN VII) Ear Scalp/eyelid fascia: Nose Mouth Palate/fauces (CN IX, X, XI)
(except TVP = V3)
Tongue (CN XII)