The hyoglossus is a flat, quadrilateral muscle connecting the hyoid bone to the lateral tongue, depressing and retracting the tongue during swallowing and speech. The lingual nerve and the submandibular ganglion lie above it, the hypoglossal nerve lies on its superficial surface, and the deep part of the submandibular gland and its duct pass around its posterior border — making the hyoglossus a surgical landmark for structures in the floor of the mouth.
| Origin | Body and greater horn of the hyoid bone |
|---|---|
| Insertion | Side of the tongue, interdigitating with the styloglossus |
| Nerve Supply | Hypoglossal nerve (CN XII) |
| Blood Supply | Lingual artery |
| Actions | Depresses the tongue; Retracts the tongue |
|---|
During swallowing, the hyoglossus depresses the tongue body while the posterior tongue and pharyngeal muscles propel the food bolus — a coordinated action essential for the oral and pharyngeal swallowing phases.
The hyoglossus is the key landmark for identifying the hypoglossal nerve, lingual nerve, and Wharton duct (submandibular duct) during submandibular gland excision and floor of mouth surgery. The lingual artery runs deep to the hyoglossus, protected from superficial approach, requiring the deep surgical approach for ligation during tongue surgery.
The hyoglossus is not accessible to external palpation but its function is assessed as part of CN XII testing through tongue depression and retraction.
Inadvertent damage to the lingual nerve or Wharton duct during floor of mouth procedures adjacent to the hyoglossus producing tongue numbness or submandibular duct obstruction.
