What is the primary function of the hypoglossal nerve (CN XII)?

The hypoglossal nerve, also known as cranial nerve XII, is primarily responsible for controlling the movements of the tongue. This function is essential for various activities, including speaking, swallowing, and manipulating food within the mouth. The hypoglossal nerve innervates the muscles of the tongue, allowing for precise movements that are necessary for articulating sounds and proper oral function.

While other cranial nerves are involved in regulating heart rate, facilitating vision, or providing sensory functions to the face, the specific role of the hypoglossal nerve is exclusively tied to motor control of the tongue muscles. This specialized function is crucial for effective communication and digestion, distinguishing it clearly from the roles of the other nerves mentioned in the options.