CSAD 334 Vestibular Pathway

for quiz 6

vestibular nerve conduction

the vestibular branch of CN VIII connects into the crista’s hair cells; the neural signal is then transferred to scarpa’s ganglion of the vestibular branch of CN VIII; this nerve conducts the electrochemical impulse to the brainstem

vestibular nucleus

similar to the CN; consists of 4 nuclei found in the brainstem’s cerebellopontine angle: superior, lateral (deiters), inferior, and medial

cerebellar involvement in the vestibular pathway

the VN projects fibers to the cerebellum, which coordinates motor movement; these VN-to-cerebellum connections facilitate the coordinated movements necessary to preserve the body’s balance

VNC projections to eyes

VNC projects fibers to nuclei in the brainstem that control eye movements; these nuclei include: abducens in pons (CN VI), trochlear in midbrain (CN IV), and oculomotor in midbrain (CN III); these keep the eyes fixed on a target while the head moves (VOR)

VNC

means vestibular nucleus-cerebellar

VOR (vestibulo-ocular reflex)

keeps eyes fixed on a target while the head moves; allows you to maintain a clear view of the world while your head is moving (e.g., when walking your vision is steady, not jumping all over)