1.    Primary afferent cell bodies:  vestibular ganglion (also called Scarpa's ganglion)

2.    Most primary axons synapse in the ipsilateral vestibular nucleus, which has several divisions:  superior, medial, lateral, inferior

3.    A few primary axons pass through the vestibular nucleus and synapse in the ipsilateral cerebellum

4.    Second order fibers project to the

a.    ipsilateral spinal cord via the lateral vestibulo-spinal tract and synapse on motoneurons

b.    ipsi- and contralateral medial vestibulo-spinal tract to the cervical spinal cord where they synapse on motoneurons controlling the muscles that determine head position

c.    cerebellum

d.    bilaterally to nuclei controlling eye position (C.N. III, IV, and VI) via the medial longitudinal fasciculus

e.    thalamus

f.    reticular formation

B.    Functions

1. motor coordination (cerebellum)

2. fixation of eye visual field (eye muscles)

3. postural adjustment (spinal motoneurons)

4. stabilize head (neck muscles)

5. sensation (cerebral cortex);  path:  project to thalamus and synapse in ventral-posterior complex; project to somatosensory areas 3a & 2 (near face region)