The thyrohyoid branch[1] (also: thyrohyoid branch of ansa cervicalis,[2] or nerve to thyrohyoid (muscle)[2][3]: 595, 600 ) is a motor branch derived from the cervical plexus[2][2][3]: 595, 600 [4]: 457, 709  formed by fibres of (the anterior ramus of[3]: 600 ) the cervical spinal nerve 1 (C1)[3]: 582 [5][6][4]: 457, 709  (and - according to some sources - cervical spinal nerve 2 (C2) as well[2][4]: 457, 709 ) that join and travel with the hypoglossal nerve (cranial nerve XII)[5] to reach the suprahyoid region,[2] branching away from CN XII distal to the superior root of ansa cervicalis[3]: 582 [4]: 709 [6] (which is a branching other fibres of C1-C2 that had traveled with the CN XII[4]: 709 ), near the posterior border of the hyoglossus muscle.

[3]: 600  The thyrohyoid branch of ansa cervicalis innervates the thyrohyoid muscle.

[2][6][3]: 582 [4]: 457, 709