Extrinsic muscles of the tongue

 

Genioglossus

Action: Depresses and protrudes the majority of the body of the tongue.

Origin: The mental spine of the mandible.

Insertion: The dorsum of the tongue.

 

 

Hyoglossus

Action: Depresses and retracts the tongue, it also makes the dorsum of the tongue more convex

Origin: The side of the body and the whole length of the greater cornu of the hyoid bone.

Insertion: The side of the tongue.

 

 

Styloglossus

Action: Draws the sides of the tongue up to create a trough for swallowing.

Origin: The anterior and lateral surfaces of the styloid process and from the sylomandibular ligament.

Insertion: Tip and sides of the tongue.

 

Innervation

The extrinsic muscles of the tongue are all innervated by the Hypoglossal nerve (cranial nerve XII).

 

Extrinsic muscles of the tongue

number 8: hyoglossus, number 9: geniohyoid, number 10: genioglossus (the styloglossus cannot be seen as it is embedded in tissue)

 image courtesy of Flickr under creative commons license: 

http://www.flickr.com/photos/michael_teller/4409892588/sizes/m/in/photostream/