Nerve supply
Taste for the anterior 2/3 of the tongue is supplied by the Facial nerve (Chorda tympani, CN7). General sensation of the anterior 2/3 is supplied by the Lingual nerve which is a branch of V3 of the Trigeminal nerve CN V.
Taste as well as general sensation for the posterior 1/3 is supplied by the Glossopharyngeal nerve (CN 9).
All intrinsic and extrinsic muscles of the tongue is supplied by the Hypoglossal nerve (CN 12), except for one of the extinsic muscles, palatoglossus, which is inervated by CN10 of the pharyngeal plexus.
Secretion of saliva by the parotid gland is controlled by presynaptic parasympathetic fibres originating in the inferior salivatory nucleus; these leave the brain via the tympanic nerve branch of glossopharyngeal nerve (CN IX), travel through the tympanic plexus (located in the middle ear), and then form the lesser petrosal nerve until reaching theotic ganglion. After synapsing in the Otic ganglion, the postganglionic (postsynaptic) fibers travel as part of theauriculotemporal nerve (a branch of the mandibular nerve (V3)) to reach the parotid gland.
Sympathetic nerves originating from Superior Cervical Ganglion and giving rise to the external carotid nerve plexus reach the gland by traveling along the external carotid arterial branches (as this structure forks into its two terminal branches, the superficial temporal artery and the maxillary artery, within the parotid gland substance)
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