The lesser petrosal nerve (also known as the small superficial petrosal nerve) is the general visceral efferent (GVE) component of the

glossopharyngeal nerve The glossopharyngeal nerve (), also known as the ninth cranial nerve, cranial nerve IX, or simply CN IX, is a cranial nerve that exits the brainstem from the sides of the upper medulla, just anterior (closer to the nose) to the vagus nerve. ...

(CN IX), carrying

parasympathetic The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of ...

preganglionic fibers from the

tympanic plexus In the tympanic cavity, the tympanic nerve (a branch of CN IX) divides into branches which, along with sympathetic fibres from the carotid plexus, form the tympanic plexus. This plexus is located on the surface of the promontory. This tympanic p ...

to the

parotid gland The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the ma ...

. It synapses in the

otic ganglion The otic ganglion is a small parasympathetic ganglion located immediately below the foramen ovale in the infratemporal fossa and on the medial surface of the mandibular nerve. It is functionally associated with the glossopharyngeal nerve and inn ...

, from where the postganglionic fibers emerge.

Structure

After arising in the tympanic plexus, the lesser petrosal nerve passes forward and then through the

hiatus for lesser petrosal nerve The hiatus for lesser petrosal nerve is a hiatus in the petrous part of the temporal bone which transmits the lesser petrosal nerve. It is located posterior to the groove for the superior petrosal sinus and posterolateral to the jugular foramen. ...

on the anterior surface of the petrous part of the

temporal bone The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples, and house the structures of the ears. ...

into the

middle cranial fossa The middle cranial fossa, deeper than the anterior cranial fossa, is narrow medially and widens laterally to the sides of the skull. It is separated from the posterior fossa by the clivus and the petrous crest. It is bounded in front by the pos ...

. It travels across the floor of the middle cranial fossa, then exits the skull via canaliculus innominatus to reach the infratemporal fossa. The fibres synapse in the

, and post-ganglionic fibres then travel briefly with the auriculotemporal nerve (a branch of V3) before entering the body of the

. The lesser petrosal nerve will distribute its parasympathetic post-ganglionic (GVE) fibers to the parotid gland via the intraparotid plexus (or

parotid plexus The parotid plexus or plexus parotideus is the branch point of the facial nerve (extratemporal) after it leaves the stylomastoid foramen. This division takes place within the parotid gland. Branches Commonly, it divides into the following branch ...

), the branches from the facial nerve in the parotid gland. The nucleus of the lesser petrosal nerve is the

inferior salivatory nucleus The salivatory nuclei are the superior salivatory nucleus, and the inferior salivatory nucleus that innervate the salivary glands. They are located in the pontine tegmentum in the brainstem. They both are examples of cranial nerve nuclei. The sup ...

References

External links

Lesser petrosal nerve diagram
* () * () (#7) * * {{Authority control Glossopharyngeal nerve Visceral motor nerves

Structure

See also

References

External links