Which cranial nerve is responsible for closing the vocal folds for airway protection during swallowing?

The cranial nerve that is responsible for closing the vocal folds for airway protection during swallowing is the vagus nerve, also known as cranial nerve X. This nerve innervates the muscles that are crucial for the closure of the vocal folds, which is essential in preventing food and liquid from entering the airway.

During the swallowing process, the closure of the vocal folds—specifically through the activity of the intrinsic laryngeal muscles, which are innervated by the recurrent laryngeal branch of the vagus nerve—enables effective airway protection. This function is vital as it helps prevent aspiration, which can lead to choking or pulmonary complications. The vagus nerve plays a significant role not only in vocal fold closure but also in coordinating the complex motor activities involved in swallowing.

In contrast, the other cranial nerves listed have different primary functions. The trigeminal nerve (cranial nerve V) is involved in sensation and movement of the jaw, the facial nerve (cranial nerve VII) controls facial expressions and taste sensations from the anterior two-thirds of the tongue, and the hypoglossal nerve (cranial nerve XII) is primarily responsible for the movement of the tongue. None of these nerves have the direct role in