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