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Greater petrosal nerve

From Wikipedia, the free encyclopedia
Greater petrosal nerve
Alveolar branches of superior maxillary nerve and sphenopalatine ganglion.
Plan of the facial and intermediate nerves and their communication with other nerves.
Details
FromFacial nerve
ToNerve of pterygoid canal
InnervatesParasympathetics to lacrimal glands
Identifiers
Latinnervus petrosus major
TA98A14.2.01.117
TA26289
FMA53417
Anatomical terms of neuroanatomy

The greater petrosal nerve (or greater superficial petrosal nerve) is a nerve of the head mainly containing pre-ganglionic parasympathetic fibres[1]: 370  which ultimately synapse in the pterygopalatine ganglion. It branches from the facial nerve (CN VII) and is derived from the parasympathetic part of the nervus intermedius component of CN VII, with its cell bodies located in the superior salivary nucleus.[2] In the connective tissue substance of the foramen lacerum,[citation needed] the greater petrosal nerve unites with the (sympathetic) deep petrosal nerve to form the nerve of the pterygoid canal (vidian nerve) which proceeds to the pterygopalatine ganglion.[2]

It forms part of a chain of nerves that provide secretomotor innervation to the lacrimal gland and mucosal glands of nasal cavity and palate.[citation needed]

Structure

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Origin

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Parasympathetic component

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Preganglionic parasympathetic fibres arise in the superior salivary nucleus of the pontine tegmentum. They join with general somatic sensory and special sensory fibres to form the nervus intermedius. The nervus intermedius exits the cranial cavity at the internal auditory meatus, and joins with the motor root of the facial nerve at the geniculate ganglion. While preganglionic parasympathetic fibres pass through the geniculate ganglion, they neither synapse, nor have their cell bodies located there.[citation needed]

Preganglionic parasympathetic fibres exit the geniculate ganglion as the greater petrosal nerve.[citation needed]

Gustatory sensory component

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The greater petrosal nerve also conveys some special sensory nerve fibres which carry gustatory (taste) sensory information from the palate[1]: 22  that are relayed to the pterygopalatine ganglion by the lesser palatine nerves and are in turn conveyed to the geniculate ganglion by the greater petrosal nerve to synapse in the ganglion.[1]: 370 

Course

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The greater petrosal nerve enters the petrous part of the temporal bone and travels anteromedially through it at a 45° angle. It emerges into the middle cranial fossa upon the anterosuperior surface of the bone[1]: 498  through the hiatus for greater petrosal nerve alongside the petrosal branch of the middle meningeal artery.[3]: 842 

In the middle cranial fossa, the nerve is situated between the two layers of the dura mater[1]: 450, 498  and passes obliquely anterior-ward[1]: 450  along a groove upon the floor of the fossa[1]: 509  - the groove for the greater petrosal nerve - that is situated upon the anterosuperior aspect of the petrous part of the temporal bone[3]: 842  and anteromedial to the arcuate eminence, and adjacent and parallel to the lesser petrosal nerve and its own groove.[1]: 509  The nerve passes deep to the trigeminal ganglion to reach the foramen lacerum.[1]: 498, 509 

At the foramen lacerum, it unites with the (sympathetic) deep petrosal nerve, forming the nerve of the pterygoid canal (which continues anterior-ward through the pterygoid canal to reach the pterygopalatine fossa and form the pterygopalatine ganglion).[1]: 498 

Clinical significance

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During surgery of the middle cranial fossa, manipulation of the dura mater may damage the greater petrosal nerve,[1]: 450, 498  causing bleeding[1]: 498  or swelling at the geniculate ganglion; this can compress the facial nerve and cause facial paralysis.[1]: 450, 498 

Additional images

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References

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  1. ^ a b c d e f g h i j k l m Sinnatamby, Chummy S. (2011). Last's Anatomy (12th ed.). Elsevier Australia. ISBN 978-0-7295-3752-0.
  2. ^ a b Lundy, Jason A.; McNary, Thomas (2023), "Neuroanatomy, Pterygopalatine Ganglion", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID 31424892, retrieved 2023-06-04
  3. ^ a b Moore, Keith L.; Dalley, Arthur F.; Agur, Anne M. R. (2018). Clinically Oriented Anatomy (8th ed.). Wolters Kluwer. ISBN 978-1-4963-4721-3.
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