Which nerve is responsible for taste sensation from the posterior 1/3rd of the tongue?

The glossopharyngeal nerve (CN IX) is responsible for sensation of taste from the posterior one-third of the tongue. This cranial nerve plays a crucial role in the gustatory function of this area, which is distinct and separate from that of the anterior two-thirds of the tongue, where the facial nerve (CN VII) is more active in taste sensation.

The glossopharyngeal nerve also innervates some of the muscles of the pharynx and contributes to the sensation of the oropharynx, which underscores its role in both taste and general sensation in the posterior area of the tongue. The presence of taste buds in this region allows the glossopharyngeal nerve to transmit signals about taste quality to the brain, thereby aiding in the overall sensory experience of flavor.

Other options represent different functions. The facial nerve is involved in taste sensation for the anterior part of the tongue, the olfactory nerve is primarily responsible for smell, and the trigeminal nerve serves mainly sensory roles related to touch, pain, and temperature but does not have a direct role in taste. Understanding the specific function of each cranial nerve is key for differentiating their roles in sensory pathways, and the glossopharyngeal nerve's specialized