CN VIII (Vestibulocochlear) Flashcards
CN VIII is what type of N?
Sensory SSA fibers
CN VII has what two distinct parts?
Cochlear (hearing)
Vestibular (balance)
The cochlear fibers arise from central portions of bipolar spiral ganglion cells of the what?
Cochlea from the organs of corti found in inner ear
The cochlear fibers transverse the what?
Internal auditory meatus to reach lateral aspect of medulla
The cochlear fibers terminate where?
Dorsal and Ventral Cochlear Nuclei in medulla
The majority of the fibers from these nuclei cross to the opposite side ending in the what?
Nuclei in trapezoid body
From here the fibers ascend through the what?
Inferior Colliculus
From inferior colliculus fibers go into what?
Medial geniculate body in thalamus
From medial geniculate body fibers finally sweep laterally to what?
Primary auditory cortex
The primary auditory cortex is located where?
In middle portion of superior temporal gyrus (brodmann 22)
What fibers arise from semicircular canals, utricle, and saccule in the inner ear?
Vestibular Fibers
The vestibular fibers enter what just medial to cochlear division of CN VIII?
Medulla
The vestibular fibers end where?
Vestibular Nuclei located in floor of 4th ventricle
Many of the fibers from vestibular nuclei pass to what?
Cerebellum through inferior cerebellar peduncle
There are a very small number of what that end up on the outer hair cells in organ of corti in inner ear?
Efferent (motor) Fibers
