Which cranial nerve is primarily responsible for taste sensation in the posterior one-third of the tongue?

Cranial Nerve IX, also known as the glossopharyngeal nerve, is primarily responsible for taste sensation in the posterior one-third of the tongue. This nerve carries taste information from this region to the brain. It has specialized sensory fibers that convey taste sensations from the taste buds located in the posterior area.

In addition to taste, Cranial Nerve IX also plays a role in other functions, such as contributing to the sensory innervation of the oropharynx and supplying certain muscles involved in swallowing. Its pathway highlights the distinct functional regions governed by cranial nerves, showcasing the importance of this nerve in flavor perception, particularly in the posterior part of the tongue.

The other cranial nerves mentioned serve different functions: Cranial Nerve VII is responsible for taste in the anterior two-thirds of the tongue; Cranial Nerve V is primarily involved in sensation for the face and does not carry taste; and Cranial Nerve XII controls tongue movements but does not have a taste sensation function. This context emphasizes the specific role of Cranial Nerve IX in the sensory perception of taste from the posterior tongue region.