The lesser petrosal nerve (also known as the small superficial petrosal nerve) is the
general visceral efferent
General visceral efferent fibers (GVE) or visceral efferents or autonomic efferents, are the efferent nerve fibers of the autonomic nervous system (also known as the ''visceral efferent nervous system'' that provide motor innervation to smooth mu ...
(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. Be ...
(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 o ...
preganglionic fibers from the
tympanic plexus 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 m ...
. It synapses in the
otic ganglion
The otic ganglion is a small parasympathetic ganglion located immediately below the foramen ovale (skull), foramen ovale in the infratemporal fossa and on the medial surface of the mandibular nerve. It is functionally associated with the glossopha ...
, 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 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
otic ganglion
The otic ganglion is a small parasympathetic ganglion located immediately below the foramen ovale (skull), foramen ovale in the infratemporal fossa and on the medial surface of the mandibular nerve. It is functionally associated with the glossopha ...
, and post-ganglionic fibres then travel briefly with the
auriculotemporal nerve
The auriculotemporal nerve is a branch of the mandibular nerve (CN V3) that runs with the superficial temporal artery and vein, and provides sensory innervation to various regions on the side of the head.
Structure
Origin
The auriculotemp ...
(a branch of V3) before entering the body of 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 m ...
.
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 branche ...
), 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 ...
.
See also
*
Tympanic nerve
*
Glossopharyngeal Nerve, Overview of visceral motor component
References
External links
Lesser petrosal nerve diagram * ()
* () (#7)
*
*
{{Authority control
Glossopharyngeal nerve
Visceral motor nerves