CRANIAL NERVE NUCLEI - LECTURE A
NBIO 401 – Wednesday, October 3, 2012
Objective for the first two cranial nerve lectures, those about cranial nerve nuclei:
-Be able to summarize the function and location of each cranial nerve nucleus.
Cranial Nerve
Nuclei Introductory
Organization
I
Optic Nerve
II
III
V
VI
VII
VIII
IX
X
XII
I
ONLY III - XII
Optic Nerve
II
III
V
VI
VII
VIII
IX
X
XII
I
CRANIAL NERVE
NUCLEI A = III - V
Optic Nerve
II
III
V
VI
VII
VIII
IX
X
XII
I
Optic Nerve
II
III
CRANIAL NERVE
NUCLEI B = VI - XII
V
VI
VII
VIII
IX
X
XII
Sensory
GSA and SSA
Mesencephalic
Trigeminal V
(jaw muscle spindles)
Main Sensory
Trigeminal V
(face touch & proprioception)
Vestibular/
Cochlear
VIII
(vestibular & auditory
signals from the inner ear)
GENERAL SOMATIC
CRANIAL NERVE NUCLEI
Motor
GSE
Oculomotor III
(eye muscles)
Trochlear IV
(eye muscles)
Abducens VI
(eye muscles)
Spinal Trigeminal V
(face pain)
Hypoglossal XII
(tongue muscles)
Sensory
GVA
GENERAL VISCERAL
CRANIAL NERVE NUCLEI
Motor
GVE
Edinger-Westphal III
(constricts pupil parasympathetic)
Superior salivatory VII
(drives salivary glands parasympathetic)
Inferior salivatory IX
(drives salivary glands parasympathetic)
Solitarius (caudal half)
VII, IX, X
(sensory information
for autonomic control)
Dorsal motor n. of X
(parasympathetic drive to
smooth muscles & organs
in chest and abdomen)
Sensory
SVA
SPECIAL VISCERAL
CRANIAL NERVE NUCLEI
Motor
SVE
Motor Trigeminal V
(chewing muscles)
Solitarius (rostral half)
VII, IX, X
(taste)
Facial VII
(muscles of
facial expression)
n. Ambiguus IX, X
(muscles of the
pharynx & larynx)
sulcus limitans
(divides motor nuclei [medial] and
sensory nuclei (lateral]).
sulcus limitans
(divides motor nuclei [medial]
and sensory nuclei (lateral]).
sulcus limitans
Motor nuclei locations
General Somatic Efferents lie close to the midline
General Visceral Efferents lay laterally to the General Somatic Efferents
Cranial Nerve
Nuclei III-V
The Oculomotor
(IIIrd) Nucleus
Edinger Westphal nucleus
(constricts the pupil)
Oculomotor nucleus
(motoneurons for
eye muscles)
Oculomotor nerve
(to eye muscles & pupil muscles)
General Somatic Efferents lie close to the midline
Sensory
GSA and SSA
Mesencephalic
Trigeminal V
(jaw muscle spindles)
Main Sensory
Trigeminal V
(face touch & proprioception)
Vestibular/
Cochlear
VIII
(vestibular & auditory
signals from the inner ear)
GENERAL SOMATIC
CRANIAL NERVE NUCLEI
Motor
GSE
Oculomotor III
(eye muscles)
Trochlear IV
(eye muscles)
Abducens VI
(eye muscles)
Spinal Trigeminal V
(face pain)
Hypoglossal XII
(tongue muscles)
Cranial Nerve
Nuclei
The Trochlear (IVth)
Nucleus
QuickTime™ and a
GIF decompressor
are needed to see this picture.
Trochlear nerve
(to eye muscles)
Trochlear nucleus
(motoneurons for
eye muscles)
General Somatic Efferents lie close to the midline
Sensory
GSA and SSA
Mesencephalic
Trigeminal V
(jaw muscle spindles)
Main Sensory
Trigeminal V
(face touch & proprioception)
Vestibular/
Cochlear
VIII
(vestibular & auditory
signals from the inner ear)
GENERAL SOMATIC
CRANIAL NERVE NUCLEI
Motor
GSE
Oculomotor III
(eye muscles)
Trochlear IV
(eye muscles)
Abducens VI
(eye muscles)
Spinal Trigeminal V
(face pain)
Hypoglossal XII
(tongue muscles)
Cranial Nerve
Nuclei III-V The
Trigeminal Nuclei
Mesencephalic trigeminal nucleus
(1° sensory neurons for
muscle spindles &
joint receptors in head)
To Thalamus
Mesencephalic
trigeminal tract
(axons bringing
unconscious
signals from muscle
spindles & joints in head)
Sensory
Axons of 1° sensory neuron
for unconscious muscle
spindle & joint receptors
(cell body in mesencephalic
trigeminal nucleus - the only
1° sensory cell body inside CNS)
Sensory
Axons signals for conscious
touch & muscle spindle/joint receptors
(cell body in ganglion outside CNS)
Trigeminal
nerve
(sensory &
motor
axons of 4
types
listed to the
right)
Motor
Axons carrying motor signals to jaw muscles
(cell body motor trigeminal nucleus)
Sensory
Axons signals for pain & temperature
(cell body in ganglion outside CNS)
Motor
trigeminal
nucleus
Motor trigeminal nucleus
(motoneurons for jaw muscles)
Main sensory trigeminal nucleus
(touch, conscious
spindle & joint from head)
Main sensory
trigeminal
nucleus
Trigeminal
nerve
Spinal
trigeminal
nucleus
Spinal trigeminal nucleus
(pain & temperature from head)
Trigeminal nerve
(afferent: touch, muscle spindle/joint,
pain & temperature from head
efferent: chewing muscles)
Motor
Trigeminal
Nucleus
(right)
Main sensory
trigeminal nucleus
(right)
Spinal
Trigeminal
Nucleus
(right)
Mesencephalic
trigeminal nucleus
(left)
Mesencephalic
trigeminal tract
(left)
Trigeminal
Nerve
(right)
Spinal
trigeminal
nucleus
(left)
Main sensory
trigeminal nucleus
(left)
Trigeminal
Nerve
(left)
Spinal trigeminal nerve (left)
(1° axons on way to
terminate in
spinal trigeminal nucleus)
Special Visceral (Branchial) Efferents lie most lateral of the motor nuclei.
Sensory
SVA
SPECIAL VISCERAL
CRANIAL NERVE NUCLEI
Motor
SVE
Motor Trigeminal V
(chewing muscles)
Solitarius (rostral half)
VII, IX, X
(taste)
Facial VII
(muscles of
facial expression)
n. Ambiguus IX, X
(muscles of the
pharynx & larynx)
ROSTRAL PONS
Medial
Longitudinal
Fasciculus
Mesencephalic trigeminal
tract & nucleus
Superior
Cerebellar
peduncle
Spinothalamic
tract
Pyramidal
Tract
Pontine
Gray matter
Medial
lemniscus
Superior cerebellar peduncle
MID PONS
Mesencephalic trigeminal tract & nucleus
(muscle spindles from chewing muscles
& jaw joint receptors)
Motor trigeminal
nucleus
Middle
Cerebellar
peduncle
MLF
Trigeminal nerve
( sensory & motor
for the head)
Spinothalamic
tract
Pyramidal
Tract
Pontine
Gray matter
Medial
lemniscus
Superior cerebellar peduncle
(fibers coming out of cerebellum)
MID PONS
Middle
Cerebellar
peduncle
MLF
Main sensory trigeminal
Nucleus (face touch)
Spinal trigeminal
tract & nucleus
Motor nucleus
of trigeminal
(chewing muscle
motoneurons)
Pyramidal
Tract
Spinothalamic
tract
Pontine
Gray matter
Medial
lemniscus
Facial nerve fibers
(looping around abducens nucleus)
CAUDAL PONS
Abducens Nucleus
(eye muscle
motoneurons)
Vestibular
nuclei
Spinal trigeminal
nucleus & tract
MLF
Inferior
cerebellar
peduncle
Facial motor
nucleus
Spinothalamic
Tract
Middle
Cerebellar
peduncle
Pyramidal
Tract
Medial
lemniscus
Pontine
Gray matter
Central
canal
Gracile
Nucleus
(touch-leg)
Gracile
Fasciculus
(touch-leg)
Cuneate
Nucleus
(touch-arm)
Spinal
trigeminal
nucleus & tract
(head pain & temp)
Spinal Accessory
Nucleus
(motoneurons for
trapezius &
sternocleidomastoid
muscles)
Medial Longitudinal
Fasciculus (MLF)
(vestibular & oculomotor information)
Pyramidal Decussation
(corticospinal fibers
crossing midline)
Cuneate
Fasciculus
(touch-arm)
Spinothalamic
Tract
Pyramids
(body pain)
(corticospinal fibers)
Spinocerebellar Tract
(sensory fibers - Muscle
spindle
& joint information to
cerebellum - leg)
Fini