Hypoglossal nerve (English)

The hypoglossal nerve (CN XII) arises as a series of rootlets from the hypoglossal nucleus of the medulla oblongata. The rootlets combine to form the nerve proper, which then exits the cranium via the hypoglossal canal. During its course, the hypoglossal nerve receives the fibers from spinal nerve C1 (and/or C2) which ‘piggyback’ the nerve, but do not mix with it. They leave the hypoglossal nerve as a series of branches: meningeal branch, superior root of ansa cervicalis, thyrohyoid branch and geniohyoid branch.The only 'true' branches of the hypoglossal nerve are the terminal lingual branches that innervate the muscles of the tongue. These branches supply all extrinsic and intrinsic muscles of the tongue, with the exception of the palatoglossus muscle, which is supplied by the vagus nerve.