Final Answer:
The glossopharyngeal nerve (CN IX) provides sensory innervation to the oropharynx, while the chorda tympani branch of the facial nerve (CN VII) carries taste sensations for the posterior 1/3 of the tongue.
Step-by-step explanation:
The glossopharyngeal nerve (CN IX) plays a crucial role in providing sensory input to the oropharynx. It innervates the mucosa of the oropharynx, carrying sensory signals that contribute to the reflexes involved in swallowing and the sensation of the throat. This nerve is essential for coordinating various functions, including the protection of the airway during swallowing.
For taste sensation in the posterior 1/3 of the tongue, the chorda tympani branch of the facial nerve (CN VII) comes into play. The chorda tympani carries taste fibers from the taste buds located on the back portion of the tongue. These taste fibers are responsible for relaying signals associated with sweet, sour, and bitter tastes. The intricate network of these nerves contributes to the complex sensory experience related to taste and swallowing.
In summary, the glossopharyngeal nerve and the chorda tympani branch of the facial nerve work together to provide sensory input to the oropharynx and taste sensation to the posterior 1/3 of the tongue, respectively.