Structure and Course of the Lesser Petrosal Nerve
- The lesser petrosal nerve is also known as the small superficial petrosal nerve.
- It is a general visceral efferent (GVE) nerve.
- It conveys pre-ganglionic parasympathetic secretomotor fibers for the parotid gland.
- The nerve passes through the petrous part of the temporal bone.
- It exits the cranial cavity through its own canaliculus.
- The nucleus of the lesser petrosal nerve is the inferior salivatory nucleus.
- It is considered a continuation of the tympanic nerve.
- After arising in the tympanic plexus, it passes through the anterior surface of the petrous part of the temporal bone.
- The nerve runs across the floor of the middle cranial fossa.
- It exits the skull via the canaliculus innominatus and enters the infratemporal fossa.
Synapse, Distribution, and Innervation of the Lesser Petrosal Nerve
- The fibers of the lesser petrosal nerve synapse at the otic ganglion.
- Post-ganglionic fibers then travel along with the auriculotemporal nerve before entering the parotid gland.
- The nerve distributes its post-ganglionic parasympathetic fibers to the parotid gland.
- This distribution occurs via the intraparotid plexus.
- The intraparotid plexus consists of branches from the facial nerve in the parotid gland.
- The lesser petrosal nerve is related to the tympanic nerve.
- It is also related to the glossopharyngeal nerve, specifically its visceral motor component.
- These nerves play a role in the innervation of the parotid gland.
References and External Links
- The information in this article is sourced from the 20th edition of Gray's Anatomy.
- Additional references include 'Gray's Anatomy: The Anatomical Basis of Clinical Practice' by Susan Standring and 'Last's Anatomy' by Chummy S. Sinnatamby.
- A diagram of the lesser petrosal nerve can be found on the website 'The Anatomy Lesson' by Wesley Norman.
- The course of the lesser petrosal nerve is discussed in an article published in Neurosurgery.
- More information on cranial nerves, including the lesser petrosal nerve, can be found on the website of Yale School of Medicine.
The lesser petrosal nerve (also known as the small superficial petrosal nerve) is the general visceral efferent (GVE) nerve conveying pre-ganglionic parasympathetic secretomotor fibers for the parotid gland from the tympanic plexus to the otic ganglion (where they synapse). It passes out of the tympanic cavity through the petrous part of the temporal bone into the middle cranial fossa of the cranial cavity, then exits the cranial cavity through its own canaliculus to reach the infratemporal fossa.
Lesser petrosal nerve | |
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![]() Mandibular division of trigeminal 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.) | |
![]() Plan of the facial and intermediate nerves and their communication with other nerves. | |
Details | |
From | tympanic plexus |
To | otic ganglion |
Innervates | parotid gland |
Identifiers | |
Latin | nervus petrosus minor |
TA98 | A14.2.01.149 |
TA2 | 6326 |
FMA | 53491 |
Anatomical terms of neuroanatomy |
Cell bodies of the lesser petrosal nerve are situated in the inferior salivatory nucleus, and are conveyed first by the glossopharyngeal nerve (CN IX) and then by the tympanic nerve to the tympanic plexus.
lesser petrosal nerve (plural lesser petrosal nerves)