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Chapter contents

Branchial motor

Visceral motor

Visceral sensory

General sensory

Special sensory

 
Cranial Nerve IX - Glossopharyngeal Page 10 of 22

Intracranial course - visceral motor component

Upon emerging from the lateral aspect of the medulla, the visceral motor fibers join the other components of CN IX to enter the jugular foramen.

Within the jugular foramen there are two glossopharyngeal ganglia which contain nerve cell bodies which mediate general, visceral, and special sensation. The visceral motor fibers pass through both ganglia without synapsing and exit the inferior ganglion with CN IX general sensory fibers as the tympanic nerve.

Before exiting the jugular foramen, the tympanic nerve enters the petrous portion of the temporal and ascends via the inferior tympanic canaliculus to the tympanic cavity.

Within the tympanic cavity the tympanic nerve forms a plexus on the surface of the promontory of the middle ear to provide general sensation. The visceral motor fibers pass through this plexus and merge to become the lesser petrosal nerve.

The lesser petrosal nerve re-enters and travels through the temporal bone to emerge in the middle cranial fossa just lateral to the greater petrosal nerve. It then proceeds anteriorly to exit the skull via the foramen ovale along with the mandibular component of CN V (V3).

Figure 9-10. Intracranial course - visceral motor component.



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Last revised: January 9, 1998