Which cranial nerve controls movement of the tongue?

Cranial nerve XII, also known as the hypoglossal nerve, is the primary cranial nerve responsible for controlling the movement of the tongue. This nerve innervates the muscles of the tongue, enabling movements essential for actions such as speaking, swallowing, and manipulating food within the mouth.

The hypoglossal nerve carries motor signals that facilitate precise movements of the tongue, such as elevation, depression, and lateral movement, which are crucial for effective oral function. Dysfunction of the hypoglossal nerve can result in difficulty with speech and the inability to properly control the tongue's movements, demonstrating the importance of this nerve in everyday activities.

In contrast, the other cranial nerves mentioned are responsible for different functions. For instance, cranial nerve VI (the abducens nerve) controls lateral eye movement, cranial nerve VII (the facial nerve) primarily controls the muscles of facial expression and taste sensations from the anterior two-thirds of the tongue, and cranial nerve IX (the glossopharyngeal nerve) is involved in taste from the posterior one-third of the tongue and also assists in swallowing. Therefore, the role of cranial nerve XII in tongue movement makes it the correct answer.