Which nerve roots supply muscles innervated by the ansa cervicalis?

The ansa cervicalis is a loop of nerves that is primarily responsible for supplying muscles in the neck, particularly those involved in functions like swallowing and some aspects of voice. It is largely formed by contributions from the first three cervical spinal nerves, specifically from the ventral rami of the first and second cervical nerves (C1 and C2), along with a contribution from the third cervical nerve (C3).

Muscles innervated by the ansa cervicalis include the sternohyoid, sternothyroid, and omohyoid muscles, which are important for maintaining the position of the larynx and hyoid bone during swallowing and speaking. The presence of C1, C2, and C3 nerve roots allows for the proper coordination and function of these muscles. This anatomical relationship clarifies why the option that includes these specific nerve roots is the correct choice for identifying the innervation of the muscles supplied by the ansa cervicalis.