Post on 13-Feb-2016
description
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The Cranial Nerves and Cranial Nerve Nuclei
of the Brain Stem
Objectives:
Learn the name and numerical designation of each of the twelve cranial nerves
Learn the names and functions of the cranial nerve nuclei of the brain stem and the nerves that arise or terminate in each of these nuclei
Learn the location of each of the cranialnerve nuclei of the brain stem on thebrain stem model
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12 pairs of Cranial Nerves arise from the forebrain and the brain stem.
I Olfactory Telencephalon II Optic Diencephalon
Cranial Nerves III through XII arise from the Brain Stem:Midbrain III Oculomotor IV TrochlearPons V Trigeminal VI Abducens VII FacialMedulla VIII Vestibulocochlear IX Glossopharyngeal X Vagus XII Hypoglossal
Cranial Nerve XI - Spinal Accessory Nerve arises from the Spinal Cord
III III
IVVI
V
VII
VIII
IX
XXIXII
Drawing A shows the ventral surface of a model of a dissected human brain. The cerebral cortex with its underlying white matter and the cerebellum have been removed. In the forebrain the caudate (c) and putamen (p) join together in the anterior, ventral area of the basal ganglia.
Cranial nerves:
OPTIC II
OCULOMOTOR III TROCHLEAR IV TRIGEMINAL V ABDUCENS VI FACIAL VII
VESTIBULOCOCHLEAR VIII GLOSSOPHARYNGEAL IX VAGUS X HYPOGLOSSAL ROOTLETS XII
SPINAL ACCESSORY XI
cp
Only the trochlear nerve IVarises from the dorsal surface of the brain stem.It courses around themidbrain to join III and VI to enter the orbit.
A
B dorsal view
c
thmidbrain
pons
medulla
spinal cord
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Cranial Nerve Nuclei
The cranial nerves innervate thehead and neck,
Cranial nerve fibers include the samefour “general” functional components as the spinal nerves :GSE, GVE, GVA and GSA.
In addition the head contains 1) “special” visceral sensory organs for olfaction and taste,2) “special” somatic sensory organs for vision, audition, and balance, and 3) a “special” group of muscles embryologically derivedfrom the branchial arches.
Thus seven functionally-distinct columns of cells in the brain stem comprise the cranial nerve nuclei:
GSE somatic motorGVE preganglionic parasympatheticSVE branchial motorGVA visceral sensorySVA olfaction and tasteGSA somatosensorySSA audition and vestibular function
The model showsa “dissection” of thecranial nerve nucleiin the tegmentum ofthe brain stem.
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GSE SOMATIC MOTOR oculomotor III trochlear IV abducens VI hypoglossal XII tongue mm.
GVE PARASYMPATHETIC Edinger Westphal III (not on model) salivatory nuclei VII, IX dorsal motor nucleus of X
SVE BRANCHIOMOTOR motor nuc. V mastication facial nuc. VII facial expression nucleus ambiguus IX, X, cXI pharynx, larynx accessory sXI trapezius, sternomastoid
IV
III
VI
XII
V
VII
sXI
MOTOR NULCEI
VIIIX
extraocular mm.
X
Nucleus ambiguusIX, X and cXI
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VIII vestibular
VIII cochlear
rost nuc solitarius VII, IX, Xcaud nuc solitarius IX, X
V principal sensory
SENSORY NULCEI
SSA AUDITION AND BALANCE vestibular VIII cochlear VIII
GSA SOMATOSENSORY trigeminal V: mesencephalic proprioception principal sensory discriminative touch spinal pain & temperature
SVA TASTE nucleus solitarius, rostral VII, IX, X GVA PAIN, etc. nucleus solitarius caudal IX, X
V spinal
V mesencehaplic
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A
B
C
D
E
F
G
H
Match each cranial nerve nucleus (A - H) with theappropriate functional designation (1 - 8).
_____ 1. receives pain input from teeth
_____ 2. innervates pharyngeal mm. _____ 3. receives input from inner ear
_____ 4. Innervates tongue mm.
_____ 5. receives fine tactile input from lips _____ 6. Innervates mm. of mastication
_____ 7. preganglionic parasympathetic
_____ 8. Innervates extraocular mm.
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Cranial Nerves and
Cranial Nerve Nuclei of the Brain Stem
Question I
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Cranial Nerves and Cranial Nerve Nuclei of the Brain StemANSWER SHEET
Question I
1. E2. D3. C4. I5. B6. G7. H8. F