THE HYPOGLOSSAL NERVE:
Netter Plate Number: 122

The hypoglossal nerve originates from the hypoglossal nucleus in the medulla oblongata.

This nerve exits the skull through the hypoglossal canal of the occipital bone.
At this point, the nerve is medial to the internal carotid artery and IJ, and it descends to the lateral aspect of the artery.
It turns forward near the angle of the mandible, loops around the occipital artery, and then passes between the external carotid and Internal jugular vessels.
Entering the submandibular triangle, this nerve travels deep to the digastric muscle, and passes superior to the greater horn of the hyoid bone on the surface of the hyoglossus muscle where it then divides into its terminal branches.

As this nerve lies upon the hyoglossus muscle of the tongue, it travels along with the vena comitans.

Its position on the hyoglossus muscle is a surgical landmark, and an important relationship.

Additionally, although fibers from the superior root of the Ansa cervicalis travel along with this nerve for 3 cm as it leaves the hypoglossal canal, however no nerve fibers are shared. This nerve supplies all of the intrinsic and extrinsic muscles of the tongue with the exception of the palatoglossus muscle.

This nerve can be used as a surgical landmark to locate the lingual artery, as the artery lies just deep and parallel to the hypoglossal nerve at the greater horn of the hyoid bone.