The ansa cervicalis (C1–C3) innervates all of the strap muscles EXCEPT which one?
- A Sternohyoid
- B Omohyoid
- C Thyrohyoid ✓
- D Sternothyroid
Correct answer: C. Thyrohyoid
Explanation
Thyrohyoid is the exception among the infrahyoid (strap) muscles — it is innervated by a branch of the hypoglossal nerve (CN XII) carrying fibers from C1 only (the first cervical nerve root fibers that hitchhike with CN XII). The other strap muscles — sternohyoid, sternothyroid, and both bellies of omohyoid — are innervated by the ansa cervicalis (C1–C3). This distinction is clinically tested and frequently asked.
Reference: BD Chaurasia's Human Anatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.