Lab 9

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Lab 9

• UPPER AND LOWER MOTOR SYSTEMS

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CORTICAL AREAS WITH UPPER MOTOR NEURONS
primary motor cortex premotor area
supplementary area cingulate motor cortex
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Haines 2-11
Primary Motor
SMA Motor planning
FEF
PMA Motor planning Of voluntary action

• Prefrontal Cortex
• Processing sensory and memory info
• Decision making

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Haines 2-24
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MUSCLE TOPOGRAPHY IN PRIMARY MOTOR CORTEX
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(No Transcript)
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Haines 3-4
INTERNAL CAPSULE Anterior Limb Genu Posterior Limb
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Haines 4-12
Thalmus medial to internal capsule
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Haines 4-4

• Posterior Limb contains
• Decending cortical spinal fibers
• Ascending thalamocortical fibers

Lentiform Nucleus Putamen Globus
Pallidus Lentiform lenticulate
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Haines 4-1
Fibers from FEF
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(No Transcript)
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Haines 5-26
Corticospinal Fibers
Corticobulbar fibers go to posterior limb of
internal capsule
Rostral Midbrain Level
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• Look at Wallerian degeneration
• P96-97

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Haines 5-25
The corticospinal fibers are arranged
topographically so that fibers to foot muscles
are most lateral and those to the neck are most
medial.
Red Nucleus
Corticospinal Fibers
Occulomotor Nucleus Nerve
Corticobulbar fibers
Rostral Midbrain Level
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Haines 5-23
Trochlear Nucleus fibers from FEF via Premotor
Area
Corticospinal Fibers
Corticobulbar fibers
Caudal Midbrain Level
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Haines 5-20
Trochlear nerve exit
PAG
Corticospinal and corticobulbar fibers mixed
Rostral Pons Level
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Haines 5-19
Trigeminal Main Motor Nucleus Supplies muscles of
mastication
Reticular Form
Corticospinal and corticobulbar fibers mixed
Rostral Pons Level
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Haines 5-17
Abducens Nucleus
Reticular Form
Facial Nerve Fibers
Corticospinal and corticobulbar fibers mixed
Rostral Medulla Level
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• See slide 5-16 in text
• www.med.harvard.edu/AANLIB/cases/caseM/mr3

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www.med.harvard.edu/AANLIB/cases/caseM/mr323
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www.med.harvard.edu/AANLIB/cases/caseM/mr317Do
it yourself
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Haines 5-12
Vestibular Nuclei
MLF
Reticular Form
Pyramid
Rostral Medulla Level
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Blackboard 23
   pyramidal tract - corticospinal/corticobulbar
fibers    medullary reticular formation   
vestibular nuclei and MLF    hypoglossal nucleus
- supplied by corticobulbar fibers (usually
bilaterally)    hypoglossal nerve fibers (travel
between pyramid and inferior olivary nucleus)
  location of nucleus ambiguus - in reticular
formation (not visible)     - sends fibers as
components of cranial nerves IX and X to supply
muscles of pharynx,       larynx, palate     -
receives input from the corticobulbar system
bilaterally
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Blackboard 11
   pyramidal tract - corticospinal/corticobulbar
fibers    medullary reticular formation   
vestibular nuclei and MLF    hypoglossal nucleus
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Haines 5-2
Lateral Corticospinal tract
Rubrospinal Tract
Lateral Motor nuclei
Lateral Vestibulospinal tract
Medial Motor nuclei
Lumbar Level
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Haines 5-3
Lateral Corticospinal tract
Rubrospinal Tract
Anterior Corticospinal tract
Medial Motor nuclei
Thoracic Level
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Haines 5-4
C7 Level