Genioglossus (Musculus genioglossus)
Educational content only — not medical advice.
Anatomy
The genioglossus is a large, fan-shaped extrinsic tongue muscle that forms the substantial bulk of the tongue body. Arising from the superior mental spine of the mandible, its fibers radiate posterosuperiorly through the entire length of the tongue dorsum down to the hyoid bone. Known as the safety muscle of the tongue, it prevents the tongue from falling backwards into the oropharynx.
Origin & insertion
From the superior mental spine (genial tubercle) on the posterior aspect of the mandibular symphysis to the entire length of the tongue dorsum and body of the hyoid bone.
Action
Protrudes the tongue forward out of the oral cavity; depresses the central part of the tongue dorsum, creating a longitudinal median groove.
Innervation
Hypoglossal nerve (cranial nerve XII).
Clinical notes
In hypoglossal nerve (CN XII) palsy, upon attempted protrusion, the tongue deviates toward the paralyzed side due to the unopposed action of the contralateral intact genioglossus; during anesthesia, loss of genioglossus tone risks complete upper airway obstruction.
Related structures
Educational references
FAQ
What is the role of the Genioglossus?
The genioglossus is a large, fan-shaped extrinsic tongue muscle that forms the substantial bulk of the tongue body. Arising from the superior mental spine of the mandible, its fibers radiate posterosuperiorly through the entire length of the tongue dorsum down to the hyoid bone. Known as the safety muscle of the tongue, it prevents the tongue from falling backwards into the oropharynx.
Why is the Genioglossus clinically important?
In hypoglossal nerve (CN XII) palsy, upon attempted protrusion, the tongue deviates toward the paralyzed side due to the unopposed action of the contralateral intact genioglossus; during anesthesia, loss of genioglossus tone risks complete upper airway obstruction.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details