Greater petrosal nerve

Greater petrosal nerve
Alveolar branches of superior maxillary nerve and sphenopalatine ganglion.
File:Gray788.png Plan of the facial and intermediate nerves and their communication with other nerves.
Details
Latin	nervus petrosus major
From	facial nerve
To	nerve of pterygoid canal
Identifiers
Dorlands /Elsevier	n_05/12566464
TA
TH	{{#property:P1694}}
TE	{{#property:P1693}}
FMA	{{#property:P1402}}
Anatomical terms of neuroanatomy [[[d:|edit on Wikidata]]]

The greater (superficial) petrosal nerve (also known as the large superficial petrosal nerve) is a nerve in the skull that branches from the facial nerve; it forms part of a chain of nerves that innervate the lacrimal gland. The fibres have synapses in the pterygopalatine ganglion (also known as the sphenopalatine ganglion).

Structure

Preganglionic parasympathetic fibres arise in the lacrimatory 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.

Preganglionic parasympathetic fibres exit the geniculate ganglion as the greater petrosal nerve. It enters the middle cranial fossa through the hiatus of the facial canal, along with the petrosal branch of the middle meningeal artery. It enters the foramen lacerum, where it joins the deep petrosal nerve (a sympathetic nerve) to form the nerve of the pterygoid canal, which passes through the pterygoid canal to reach the pterygopalatine ganglion.

Function

The greater (superficial) petrosal nerve carries parasympathetic preganglionic fibers from the facial nerve. The greater petrosal nerve continues as the nerve of the pterygoid canal and ultimately synapses with the pterygopalatine ganglion whose parasympathetic postganglionic fibers synapse with the lacrimal gland and the mucosal glands of the nose, palate, and pharynx.

Additional images

• Gray789.png

  Course and connections of the facial nerve in the temporal bone.

• Gray841.png

  Sympathetic connections of the sphenopalatine and superior cervical ganglia.

• Head lateral gr petrosal nerve.jpg

  Head lateral gr petrosal nerve

External links

• cranialnerves at The Anatomy Lesson by Wesley Norman (Georgetown University) (VII)
• University of Michigan Medical School "Dissector Answers - Ear and Nasal Cavity"