Lesser petrosal nerve

The lesser petrosal nerve consists of parasympathetic fibers. It leaves the tympanic plexus to synapse in the otic ganglion, and eventually provide parasympathetic innervation to the parotid gland.

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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 of lesser petrosal nerve. It then exits the middle cranial fossa through foramen ovale to the otic ganglion where its parasympathetic fibers synapse. From the otic canglion, 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 As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.