[UW Anatomy |
Contents]
Function:
Reflex control of the head and body via pathways that convey
information from receptors in the three pairs of semicircular canals
and the saccule and utricle to the spinal cord.
Pathway:
Peripheral processes of cells in vest. ganglion end on hair cells in
the receptors. Central processes comprise the vestibular nerve which
terminates in the four vest. nuc. (lie in rost. medulla and pons;
important nuclei to identify in sections=inferior and medial [level
#4]). Neurons in lat. vest. nuc. project to IPSI. spinal cord via
LAT. vestibulospinal tract (L.V.S.T.; vent. funic.). Cells in med.
vest. nuc. project to BOTH sides (contra. is bigger) of spinal cord
via MED. vestibulospinal tract (M.V.S.T.; vent. funic.).
Deficits:
Lesion of vestibular nuc. or nerve = IPSI. stumbling and falling.
That is, you stumble TOWARD the lesion, since the normal side is OK
and kind of PUSHING you toward the weak (lesion) side.
Other Note:
THE ASSOCIATION OF THE VEST. NUC. WITH THE ABDUCENS (EYE MOVEMENTS)
IS COVERED IN 12b.
Last Modified: March 7, 1995
Maintained by: neuro714@macc.wisc.edu