Upper & Lower Motor Systems Lab 9 Upper & Lower Motor Systems

1 SMA FEF PMA What is the ~location of the: Prefrontal Cortex? Motor planning FEF PMA Motor planning Of voluntary action Prefrontal Cortex Processing sensory and memory info Decision making What is the ~location of the: Prefrontal Cortex? PMA (premotor area)? SMA (supplementary motor area) FEF (frontal eye field)

1 2

1 2 3

1 4 2 Thalamus 3

Thalamus 1 2 Lentiform Nucleus 3

1 2 3 Putamen (lentiform nucleus)

1 2 3 4 ant. limb, Int. capsule (frontal eye field fibers) head of caudate nucleus frontal horn, lateral ventricle 2 3 optic chiasm 4 putamen ICA

2 3 4 1 5 6 Post. limb, int. capsule: corticospinal + corticopontine + thalamocortical fibers 3 Body of lateral ventricle thalamus 4 descending cortical fibers in crus cerebri of midbrain 1 5 III Ventricle Lentiform nucleus (only putamen is visible) 6

What descending fibers from the primary motor cortex have degenerated in the indicated areas?

Midbrain/Thalamic Junction Abbreviations: CS = corticospinal CB = corticobulbar Position of: oculomotor nucleus + nerve roots 3 2 4 CB 1 CS optic tract 6 CB CS 7 Oculomotor nerve roots nucleus 8 9 10 Red nucleus 5 RED NUCLEUS Midbrain/Thalamic Junction

descending cortical fibers 1 2 MLF Trochlear nucleus 3 Caudal Midbrain

Mid Pons 4 3 5 7 2 6 1 8 reticular formation with descending rubrospinal fibers 3 descending cortical fibers 5 descending cortical fibers trigeminal nerve & nerve roots 7 motor nuc. of V 2 6 1 Nerve Roots of V motor nucleus of V 8 Mid Pons

Caudal Pons 5 8 nucleus 9 fibers 4 3 7 nerve 2 1 10 11 nerve nucleus 6 Reticular formation with reticular nuclei & descending rubro- spinal fibers 5 8 nucleus facial nucleus descending cortical fibers 9 fibers descending cortical fibers abducens nerve roots 4 3 7 nerve exit of facial nerve roots 2 facial nucleus 1 Facial nerve roots 10 nucleus abducens nucleus exit of VI nerve roots 11 nerve abducens nucleus 6 Caudal Pons

Rostral Medulla 3 4 2 nerve 8 1 nerve 9 11 10 6 5 7 reticular formation with reticular nuclei + & descending rubrospinal & reticulospinal fibers Pyramidal (corticospinal) tract 4 3 Hypoglossal nerve roots 2 nerve 8 pyramidal tract 1 nerve Vagal Nerve roots nuc. ambiguus 9 Hypoglossal nuc. 11 10 Vest. Nuc. nucleus ambiguus vestibular nuclei 6 5 hypoglossal nucleus 7 Rostral Medulla

Caudal Medulla 1 crossing 2 crossing Pyramidal decussation general position of pyramidal decussation 2 crossing Caudal Medulla

. . Cervical Spinal Cord 2 5 4 1 3 6 Position of: ventral corticospinal, vestibulospinal, & reticulospinal tracts ventral horn with LMN 5 lateral corticospinal & rubrospinal tracts lateral corticospinal tract + rubrospinal tract 4 1 3 medial & lateral motor nuclei in ventral horn ventral corticospinal, vestibulo- spinal, & reticulospinal tracts 6 . . Cervical Spinal Cord

What is the ~location of the: Corticospinal Fibers? Corticobulbar fibers – go to genu of internal capsule What is the ~location of the: Corticospinal Fibers? Corticobulbar Fibers? Rostral Midbrain Level

What is the ~location of the: Corticobulbar Fibers? Red Nucleus Corticospinal Fibers Occulomotor Nucleus Nerve Corticobulbar fibers What is the ~location of the: Corticobulbar Fibers? Corticospinal Fibers? Red Nucleus? Oculomotor Nucleus & Nerve? Rostral Midbrain Level

Trochlear Nucleus – fibers from FEF via Premotor Area Corticospinal Fibers Corticobulbar fibers What is the ~location of the: Corticobulbar Fibers? Corticospinal Fibers? Trochlear Nucleus? Caudal Midbrain Level

Trochlear nerve exit PAG Corticospinal and corticobulbar fibers mixed What is the ~location of the: Corticobulbar & Corticospinal Fibers? PAG? Trochlear Nerve? Rostral Pons Level

Trigeminal Main Motor Nucleus Supplies muscles of mastication Reticular Formation Corticospinal and corticobulbar fibers mixed What is the ~location of the: Corticobulbar & Corticospinal Fibers? Trigeminal Motor Nucleus? Reticular Formation? Rostral Pons Level

Abducens Nucleus Facial Nerve Fibers Reticular Formation Corticospinal and corticobulbar fibers mixed What is the ~location of the: Corticobulbar & Corticospinal Fibers? Facial Nerve Fibers? Abducens Nucleus? Reticular Formation? Rostral Medulla Level

Hypoglossal Nerve Roots & Nucleus Vestibular Nuclei MLF Reticular Formation Pyramid What is the ~location of the: Pyramid? MLF? Vestibular Nuclei? Reticular Formation? Hypoglossal Nucleus & Nerve Roots? Rostral Medulla Level

Lateral Corticospinal tract Rubrospinal Tract Lateral Motor nuclei Lateral Vestibulospinal tract What is the ~location of the: Lateral Corticospinal Tract? Medial Motor nuclei Rubrospinal Tract? Lateral Motor Nuclei Lateral Vestibulospinal Tract? Medial Motor Nuclei Lumbar Level

Lateral Corticospinal tract Rubrospinal Tract Anterior Corticospinal tract Medial Motor nuclei What is the ~location of the: Lateral Corticospinal Tract? Rubrospinal Tract? Medial Motor Nuclei Anterior Corticospinal Tract? Thoracic Level

Lateral Corticospinal tract Rubrospinal Tract What is the ~location of the: Lateral Corticospinal Tract? Rubrospinal Tract? C7 Level