Which cranial nerve is responsible for taste sensation on the anterior two-thirds of the tongue?

The correct answer is the facial nerve, which is cranial nerve VII. This nerve is primarily responsible for taste sensation on the anterior two-thirds of the tongue. The taste buds in this region send impulses via the chorda tympani, a branch of the facial nerve, to the brain, where these taste sensations are processed.

Understanding the function of cranial nerve VII is essential for recognizing how sensory information is relayed from the tongue to the brain, which is critical during a HEENT assessment. This ability to assess and identify taste sensations can help in diagnosing various conditions that might affect taste perception or the integrity of the nerve following an injury or infection.

The other cranial nerves listed serve different functions. For example, the hypoglossal nerve primarily controls tongue movements, while the trigeminal nerve is involved in facial sensation and movement of mastication but does not transmit taste sensations from the anterior tongue. The glossopharyngeal nerve handles taste sensations from the posterior one-third of the tongue and contributes to the gag reflex, which is distinct from the anterior two-thirds innervation.