Exam 2: CN8 Flashcards
CN 8 purely
Sensory
CN 8 composed of 2 Nerves:
Vestibular
Cochlear
Vestibular N terminates in
Vestibular nuclear complex
Vestibular nuclear complex consists of 4 parts
Superior
Medial - most synapse
Lateral
Inferior
Fibers carried in vestibular nerve arise from cell bodies located in
Vestibular ganglion
Vestibular ganglion located
Internal acoustic meatus
Cochlear nerve termites in
2 cochlear nuclei: anterior and posterior
Cochlear nerve composed of axons from
Spiral ganglion
In cochlear nerve, peripheral processes extend from __ to ___
Spiral ganglion
Spiral organ
2 cochlear nuclei located in
Posterior, superior MO
From cochlear nuclei, axons synapse in
Trapezoid nuclei
Axons from trapezoid nuclei form
Lateral lemniscus
Peripheral processes from vestibular ganglion extend to 3 inner ear structures
Saccule
Utricle
Semicircular ducts
Vestibular nuclei located in
MO, floor of rhomboid fossa
Most vestibular nerve fibers terminate in
Medial vestibular nucleus
Other vestibular nerve fibers travel to
Cerebellum via inferior cerebellar peduncle
AO of CN8
Cerebellopontine angle
CN8 travels in ____ to IAM
Posterior cranial fossa
Cochlear N carries ___ fibers
30-40,000
Vestibular nerve carries
20,000 fibers
Inferior branch of vestibular nerve composed of
Saccular nerve
Posterior ampullary nerve
Superior branch of vestibular nerve formed by
Lateral and anterior ampullary nerves
Utricle supplied by
Branch from lateral ampullary nerve
Branch directly from superior branch
Superior branch of vestibular nerve sends branch directly to saccule, called
Voit’s nerve
Saccule and utricle supplied by ___
2 nerves
__ can be first sign of Meniere’s disease
Tinnitus
Acoustic neuroma aka
Vestibular schwannoma
