Cranial nerves Apparent origins
Vestibulocochlear (CN VIII) Cerebllopontine recess
Glossopharyngeal (CN IX) Lateral aspect of superior medulla
Vagus (CN X) Lateral aspect of medulla
Accessory (CN XI) Cranial: lateral aspect of medulla
Spinal: lateral aspect of cord (C1-C5/6)
Hypoglossal (CN XII) M.O. sulcus btwn pyramid & olivary nucleus
Cranial nerves Patent opening
Vestibulocochlear (CN VIII) Internal acoustic meatus
Glossopharyngeal (CN IX) Jugular Foramen
Vagus (CN X) Jugular Foramen
Accessory (CN XI) Jugular Foramen
Hypoglossal (CN XII) Hypoglossal canal
Lower motor nuerons
Nucleus ambiguus: CN IX, X, XI
Hypoglossal nucleus: CN XII
, Vesitbulocochlear nerve
Sensory only
2 separate nerves in one sheath
4 neuron pathway
Vestibular nerve
Nucleus of termination:
– Superior (Bechterew)
– Medial (Schwalbe) MC
– Lateral (Deiter) [Vestibulospinal tract, balance & extensors]
– Inferior
Some nuclei go directly to cerebellum via inferior cerebellar peduncle
3 in medulla oblongata on floor of rhomboid fossa
Posterior cranial fossa
Cell bodies: (Bipolar neurons) Internal acoustic meatus
-located in the vestibular ganglion [within internal acoustic meatus]
Temporal bone
Cochlear nerve
Nucleus of termination:
-cochlear nuclei (anterior & posterior) [in CNS] In posterior, superior medulla oblongata
Cell bodies: (Bipolar neurons)
-located in spiral ganglion [within the cochlea]
dendrites span a short distance to the spiral organ of Corti
Clinical considerations:
-acoustic neuroma [hearing prob]
-vestibular shwannoma [equilibrium prob] Info travels distal Proximal
-tinnitus [ringing of the ears (1st symptom of Ménière’s disease)]
-cochlear implants [only effective for sensorineural hearing loss]
-vestibular disease [different than cervicogenic vertigo]
ALL fibers carried in C.N. VIII originate in ear and terminate in CNS
Saccule & utricle receptors are the same: Maculae
Semicircular receptors: Cristae
Medial vestibular
nucleus
Ant/Sup semicircular duct
Vestibular ganglion
Lat. Semicircular duct
branch
SUP. larger ,
2
· Utricle
Saccule
VoitsNerve 2
INF.
Posterior semicircular duct
Vestibulocochlear (CN VIII) Cerebllopontine recess
Glossopharyngeal (CN IX) Lateral aspect of superior medulla
Vagus (CN X) Lateral aspect of medulla
Accessory (CN XI) Cranial: lateral aspect of medulla
Spinal: lateral aspect of cord (C1-C5/6)
Hypoglossal (CN XII) M.O. sulcus btwn pyramid & olivary nucleus
Cranial nerves Patent opening
Vestibulocochlear (CN VIII) Internal acoustic meatus
Glossopharyngeal (CN IX) Jugular Foramen
Vagus (CN X) Jugular Foramen
Accessory (CN XI) Jugular Foramen
Hypoglossal (CN XII) Hypoglossal canal
Lower motor nuerons
Nucleus ambiguus: CN IX, X, XI
Hypoglossal nucleus: CN XII
, Vesitbulocochlear nerve
Sensory only
2 separate nerves in one sheath
4 neuron pathway
Vestibular nerve
Nucleus of termination:
– Superior (Bechterew)
– Medial (Schwalbe) MC
– Lateral (Deiter) [Vestibulospinal tract, balance & extensors]
– Inferior
Some nuclei go directly to cerebellum via inferior cerebellar peduncle
3 in medulla oblongata on floor of rhomboid fossa
Posterior cranial fossa
Cell bodies: (Bipolar neurons) Internal acoustic meatus
-located in the vestibular ganglion [within internal acoustic meatus]
Temporal bone
Cochlear nerve
Nucleus of termination:
-cochlear nuclei (anterior & posterior) [in CNS] In posterior, superior medulla oblongata
Cell bodies: (Bipolar neurons)
-located in spiral ganglion [within the cochlea]
dendrites span a short distance to the spiral organ of Corti
Clinical considerations:
-acoustic neuroma [hearing prob]
-vestibular shwannoma [equilibrium prob] Info travels distal Proximal
-tinnitus [ringing of the ears (1st symptom of Ménière’s disease)]
-cochlear implants [only effective for sensorineural hearing loss]
-vestibular disease [different than cervicogenic vertigo]
ALL fibers carried in C.N. VIII originate in ear and terminate in CNS
Saccule & utricle receptors are the same: Maculae
Semicircular receptors: Cristae
Medial vestibular
nucleus
Ant/Sup semicircular duct
Vestibular ganglion
Lat. Semicircular duct
branch
SUP. larger ,
2
· Utricle
Saccule
VoitsNerve 2
INF.
Posterior semicircular duct
