Which nerve roots supply muscles innervated by the ansa cervicalis?

The ansa cervicalis is a loop of nerves derived from the cervical plexus and primarily supplies the infrahyoid muscles, which play a key role in functions such as swallowing and movements of the hyoid bone. The ansa cervicalis is formed by contributions from the first three cervical spinal nerves, specifically C1, C2, and C3.

C1 fibers are responsible for providing the innervation to the sternohyoid, sternothyroid, and omohyoid muscles, while C2 and C3 contribute to the vagus nerve's function and the sensory aspects of the cervical plexus. This means that the muscles innervated by the ansa cervicalis mainly receive their motor supply from these C1, C2, and C3 nerve roots.

In exploring the other options, C3, 4, 5 do not correspond to the correct nerves supplying the ansa cervicalis, as C4 and C5 are not involved in the innervation of the infrahyoid muscles. Similarly, C5, 6, 7 pertain to other musculature, particularly in the upper limb, and are not relevant to the functions of the ansa cervicalis. Finally, while C2 and