Glossopharyngeal nerve

Glossopharyngeal nerve
Plan of the upper portions of the glossopharyngeal, vagus, and accessory nerves.
Course and distribution of the glossopharyngeal, vagus, and accessory nerves. (Label for glossopharyngeal is at upper right.)
Details
To	tympanic nerve
Innervates	stylopharyngeus
Identifiers
Latin	nervus glossopharyngeus
MeSH	A08.800.800.120.290
NeuroLex ID	Glossopharyngeal nerve fiber bundle
Dorlands /Elsevier	n_05/12565844
TA	A14.2.01.135
FMA	50870
Anatomical terms of neuroanatomy []

The glossopharyngeal nerve, known as the ninth cranial nerve (CN IX), is a mixed nerve that carries afferent sensory and efferent motor information. It exits the brainstem out from the sides of the upper medulla, just rostral (closer to the nose) to the vagus nerve. The motor division of the glossopharyngeal nerve is derived from the basal plate of the embryonic medulla oblongata, while the sensory division originates from the cranial neural crest.

From the anterior portion of the medulla oblongata, the glossopharyngeal nerve passes laterally across or below the flocculus, and leaves the skull through the central part of the jugular foramen. From the superior and inferior ganglia in jugular foramen, it has its own sheath of dura mater. The inferior ganglion on the inferior surface of petrous part of temporal is related with a triangular depression into which the aqueduct of cochlea opens. On the inferior side, the glossopharyngeal nerve is lateral and anterior to the vagus nerve and accessory nerve.

In its passage through the foramen (with X and XI), the glossopharyngeal nerve passes between the internal jugular vein and internal carotid artery. It descends in front of the latter vessel and beneath the styloid process and the muscles connected with it, to the lower border of the stylopharyngeus. It then curves forward, forming an arch on the side of the neck and lying upon the stylopharyngeus and middle pharyngeal constrictor muscle. From there, it passes under cover of the hyoglossus muscle and is finally distributed to the palatine tonsil, the mucous membrane of the fauces and base of the tongue, and the serous glands of the mouth.