Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
The pseudounipolar neurons of the inferior ganglion of the glossopharyngeal nerve provide sensory innervation to areas around the tongue and pharynx. More specifically:
innervation of taste buds on the posterior 1/3 of tongue
The central processes of the neurons which provide taste sensation synapse in the rostral portion of the solitary nucleus (also called the gustatory nucleus). The central processes of the neurons which provide general sensory information synapse in the spinal trigeminal nucleus. Finally, the central processes of the neurons which innervate the carotid sinus and carotid body synapse in the caudal portion of the solitary nucleus.
Tympanic nerve
The tympanic nerve is the first branch of the glossopharyngeal nerve. It branches at the level of the inferior ganglion. Importantly, the axons which form the tympanic nerve do not synapse in this ganglion or have their cell bodies in it. The neuron cell bodies of the axons which form the tympanic nerve are found in the inferior salivatory nucleus and superior ganglion of the glossopharyngeal nerve.
References
Rubin, Michael (2017). Netter's Concise Neuroanatomy. Safdieh, Joseph E., Netter, Frank H. (Frank Henry), 1906-1991 (Updated ed.). Philadelphia, PA: Elsevier. pp. 253–256. ISBN9780323480918. OCLC946698976.
Plan of upper portions of glossopharyngeal, vagus, and accessory nerves. (Inferior ganglion of the glossopharyngeal nerve labeled as ‘petrous gang’.