The is the ninth of twelve
Cranial Nerves . It exits the brainstem out from the sides of the upper
Medulla , just rostral (closer to the nose) to the
Vagus Nerve .
There are a number of functions of the glossopharyngeal nerve:
The glossopharyngeal nerve, being mostly sensory, does not have a
Cranial Nerve Nucleus of its own. Instead it must project into many different structures in the brainstem:
- '') supplied by nerve IX.
From the
Medulla Oblongata , the glossopharyngeal nerve passes lateralward across the
Flocculus , and leaves the skull through the central part of the
Jugular Foramen , in a separate sheath of the
Dura Mater , lateral to and in front of the vagus and accessory nerves.
In its passage through the jugular foramen, it grooves the lower border of the
Petrous Part of the
Temporal Bone ; and, at its exit from the
Skull , passes forward 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
Constrictor Pharyngis Medius .
Thence it passes under cover of the
Hyoglossus , and is finally distributed to the
Palatine Tonsil , the
Mucous Membrane of the
Fauces and base of the
Tongue , and the mucous glands of the
Mouth .
The
Gag Reflex is absent in patients with damage to the glossopharyngeal nerve as it is responsible for the afferent limb of the reflex.
