Final answer:
Tactile sensations of the tongue are conveyed to the ventral posterior nucleus of the thalamus. This nucleus processes both gustatory and somatosensory information from the cranial nerves before it reaches the cerebral cortex for conscious perception.
Step-by-step explanation:
The tactile sensations of the tongue are conveyed to the ventral posterior nucleus of the thalamus. This is the target nucleus for both gustatory (taste) and somatosensory (touch, pain, temperature) sensations from the tongue. The sensory pathway involves the facial and glossopharyngeal cranial nerves transmitting information to the solitary nucleus in the brain stem. From the solitary nucleus, axons project to the ventral posterior nucleus, which then sends signals to the cerebral cortex for processing and conscious perception.
The medial geniculate nucleus is involved in the auditory pathway, while the lateral geniculate nucleus is involved in the visual pathway; therefore, neither of these nuclei are associated with the tactile sensations of the tongue. The dorsal posterior nucleus is not a recognized structure in the standard nomenclature of brain anatomy associated with these sensations.