| Nerve: Lesser petrosal nerve | |
|---|---|
| Plan of the facial and intermediate nerves and their communication with other nerves. | |
| Mandibular division of trifacial nerve, seen from the middle line. The small figure is an enlarged view of the otic ganglion. (Small petrosal labeled at center top and bottom right.) | |
| Latin | nervus petrosus minor |
| Innervates | parotid gland |
| From | tympanic plexus |
| To | otic ganglion |
The lesser petrosal nerve consists of parasympathetic fibres. It exits the jugular foramen with the glossapharyngeal nerve, only to reenter the skull through the tympanic canaliculus. It then leaves the tympanic plexus to exit the skull through the foramen ovale and synapse in the otic ganglion. Post-synaptic parasympathetic fibers then provide innervation to the parotid gland.
The tympanic plexus has parasympathetic (preganglionic) roots which contribute to the lesser petrosal nerve. Parasympathetic contribution is from the tympanic nerve which branches from the glossopharyngeal nerve (CN IX) in the jugular foramen.
The lesser petrosal nerve exits the temporal bone and enters the middle cranial fossa through the hiatus for lesser petrosal nerve. In some individuals it instead passes through the foramen ovale. It then exits the middle cranial fossa through foramen ovale to the otic ganglion where its parasympathetic fibers synapse. From the otic ganglion, its fibers hitchhike with the auriculotemporal nerve (from V3) to eventually innervate the parotid gland.
The geniculate ganglion also communicates with the lesser petrosal nerve.
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.
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