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CRANIAL NERVES - LECTURE B

NBIO 401 – Friday, October 8, 2009

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Abducensnucleus

Abducensnerve

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Facialnucleus

Facialnerve

Genu of the Facial

nerve

Abducensnucleus

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Abducens Nucleus(eye muscle motoneurons)

Facial nerve fibers(looping around the abducens nucleus)

Facial motor nucleus(muscles of

facial expression)

Facial motor nucleus

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Solitary tract(inside)

Solitary nucleus(outside)

Spinal trigeminalnucleus

Abducensnucleus

Superior salivatory nucleus

Facial intermediate nervepart of facial nerve carrying:Motor1) motor output from the superior salivatory nucleusto some salivary glands (GVE)Sensory1) taste information fromthe anterior 2/3 of the tongue tosolitary nucleus via the solitarytract (SVA)2) touch information from asmall patch of skin on the ear andbehind the ear to spinal trigeminalnucleus (GSA)Facial

intermediatenerve

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Vestibulocochlear Nerve VIIICochlear component

(carries auditory signals from thecochlea to the cochlear nucleus)

Superior cochlear nucleus

Superior cerebellar peduncle

Inferior cerebellar peduncle

Middle cerebellar peduncle

Spinocerebellar fibers(on route to the cerebellum)

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Vestibulocochlear Nerve VIIIvestibular component

(carries vestibular signals from thevestibular labyrinth to the vestibular nuclei)

Inferiorvestibularnucleus

Medialvestibularnucleus

InferiorCerebellarpeduncle

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VestibulocochlearNerve VIII

Superior Cochlearnucleus

Vestibular nuclei

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Mediallemniscus

SpinothalamicTract

PyramidalTract

Spinal trigeminalnucleus & tract

HypoglossalNucleus

Inferior olive

nucleus

Vestibularnuclei

Abducensnerve

(to eye muscle)

Cochlear Nucleus(auditory information)

MLF

PontineGray matter

(relay signals to cerebellum)

Inferior cerebellarpeduncle

(spinocerebellarfibers to cerebellum)

Solitary tract& nucleus

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Nucleus Ambiguus(motoneurons forlarynx & pharynx

muscles)

Glossopharyngeal nerve IXcarries:Motor1) signals to the pharynxfrom nucleus ambiguus2) motor output from the inferiorsalivatory nucleus to some salivaryglandsSensory1) taste information from posterior1/3 of tongue to the solitary nucleusvia the solitary tract.2) touch information from the posterior 1/3 of the tongue, pharynx, some skin around the ear, internal surface of ear drumto the spinal trigeminal tract3) Pressure signals from the carotidartery

Solitary nucleus & tract

Spinal trigeminal Nucleus

Inferior salivatory nucleus

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Solitarynucleus & tract

Nucleusambiguus

Spinaltrigeminalnucleus

Dorsalmotor nucleusof the Vagus

Roots of the vagus nerve X carries:Motor1) motor signals to larynx & pharynx muscles from motoneurons in nucleus ambiguus.2) parasympathetic output to the larynx & pharynx & to organs of the chest & abdomen from the dorsal motor nucleus of the vagusSensory1) touch signals from pharynx, external ear canal, external side of the ear drum, & skin of the earto the spinal trigeminal nucleus.2) taste information from the epiglottus to the solitary nucleus3) sensory signals from the larynx, trachea, esophagus, chest & abdomen viscera, & pressure & chemoreceptorsin the aorta to the caudal part of the solitary nucleus.

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Medial lemniscus(touch information

from body)

SpinothalamicTract

SpinocerebellarTract

Pyramids

Spinal trigeminalnucleus & tract

HypoglossalNucleus(tongue

motoneurons)

Lateralcuneatenucleus

Inferior olive nucleus(big input to cerebellum)

Vestibularnuclei

Hypoglossal nerve(motor commands to tongue)

MLF

DMX

Nucleus Ambiguus(motoneurons for larynx

& pharynx muscles)Solitary tract

& nucleus

Vagus Nerve Rootlet(motor commandsto viscera in body)

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Spinalaccessory

nerve

Spinal accessory nucleus(motoneurons for

sternocleidomastoid & trapezius muscles)

Spinalaccessory

roots

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Cuneate fasciculus

Pyramidal DecussationSpinothalamic

TractPyramidal tract

Spinaltrigeminal

nucleus & tract

Cuneate nucleusGracile Nucleus

Gracile fasciculus

MLF

Spinal AccessoryNucleus

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Hypoglossalnerve

Hypoglossal nuclei(motoneuron fortongue muscles)

Dorsal motor nucleiof the vagus

Solitarynucleus& tract

Spinal trigeminalnucleus & tract

Nucleusambiguus

Vestibularnuclei

External cuneatenucleus

Inferior olive

Pyramidaltract

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Spinal trigeminalnucleus & tract

HypoglossalNucleus

Lateral cuneatenucleus

IVthventricle

Vestibularnuclei

DMX

Solitary tract& nucleus

Inferior olive

Pyramidal tract

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Trochlearnerve

Trochlearnucleus

Oculomotornucleus

Oculomotornerve

Abducensnucleus

Abducensnerve

Hypoglossalnucleus

Hypoglossalnerve

Somatic Motor Nuclei

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Trigeminalmotor nucleus

Trigeminalnerve

Facialmotor nucleus

Facialmotor nerve

Nucleusambiguus

Nucleus ambiguusaxons bound for

glossopharyngeal& vagus nerves

Special visceral (Branchial) Motor Nuclei

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Dorsal motor nucleus of the vagus

Edinger-Westphalfibers bound for

the oculomotor nerve

Axons from the dorsal motor nucleusof the vagus bound for the vagus nerve

Axons from the inferiorsalivatory nucleus bound

for the glossopharyngeal nerve

Inferior salivatory nucleus

Superior salivatory nucleus

Axons from thesuperior salivatory nucleusbound for the facial nerve

General Visceral Motor Nuclei

Edinger-Westphalnucleus

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Spinaltrigeminal

nerve

Spinaltrigeminalnucleus

Mesencephalictrigeminal nucleus

Main sensorytrigeminal nucleus Mesencephalic

trigeminal tractTrigeminal nerve

(touch, conscious& unconscious proprioception, pain & temperature

from the head to main sensorytrigeminal nucleus, mesencephalic

trigeminal nucleus & spinaltrigeminal nucleus)

Vagus nerve(touch from ear

& pharynx tospinal trigeminal)

GlossopharyngealNerve

(touch from ear & pharynxto spinal trigeminal)

Facial intermediate nerve(touch from ear to spinal

trigeminal nucleus)

Somatic Sensory Nuclei

Glossopharyngeal nerve (taste from posterior 1/3

of tongue to solitary nucleus)

Facial intermediateNerve (taste from anterior2/3 of tongue to solitary

nucleus)

Vagus nerve(taste from epiglottus to rostral solitary nucleus,

signals from the trachea, esophagus,chest, abdomen & aorta to

caudal part of solitary nucleus)

Visceral Sensory Nuclei

GENICULATEGANGLION

PETRO SALGANGLIO N

SOLITARYNUCLEUS

C aud a l 1 /2(au to nom ic sen sory

processing)(GVA)

NODO SEGANGLIO N

P O S TE R IO R 1/3

R ostra l 1 /2(tas te )(SVA)

TONGUE

A N T E R IO R 2/3

E P IG LO T TIS

V II - FA C IA L

IX - G L O S S O P H A R Y N G E A L

X - VA G U S

( fac ia lin te rm e d ia te

nerve)