Final answer:
The ansa cervicalis provides motor innervation to the infrahyoid muscles, including the sternohyoid, omohyoid, sternothyroid, and thyrohyoid muscles, which are important for swallowing and speech.
Step-by-step explanation:
The ansa cervicalis is a loop of nerves that provides motor innervation to several muscles in the neck. Specifically, it innervates the infrahyoid muscles, which include the sternohyoid, omohyoid, sternothyroid, and thyrohyoid muscles. These muscles are primarily responsible for positioning and stabilizing the hyoid bone, which is important for swallowing and speech functions. It is important to note that while other muscles in the cervical region may be innervated by other nerves, such as the accessory nerve innervating the sternocleidomastoid and trapezius muscles, the ansa cervicalis specifically targets the infrahyoid group.