Which cranial nerve controls muscles involved in swallowing?

The glossopharyngeal nerve, also known as cranial nerve IX, is crucial for controlling the muscles involved in swallowing. This nerve is responsible for several functions, including the sensation in the pharynx and posterior one-third of the tongue, as well as the motor control needed for the pharyngeal muscles during the swallowing process.

Its role in swallowing also involves the coordination of the muscles in the throat, which facilitate the movement of food from the mouth down into the esophagus. By transmitting motor signals to these muscles, the glossopharyngeal nerve plays a key role in initiating the swallowing reflex and ensuring it occurs smoothly.

Other cranial nerves listed have different primary functions. The accessory nerve primarily innervates certain neck muscles rather than participating in the act of swallowing. The hypoglossal nerve mainly controls the movements of the tongue, which can aid in the process but does not directly control the muscles of swallowing. The trigeminal nerve is primarily responsible for sensation in the face and motor functions like chewing, not swallowing. Therefore, the glossopharyngeal nerve is the correct answer due to its direct involvement in the mechanics of swallowing.