UPPER AND LOWER MOTOR SYSTEMS Lab 9 UPPER AND LOWER MOTOR SYSTEMS

CORTICAL AREAS WITH UPPER MOTOR NEURONS primary motor cortex premotor area supplementary area cingulate motor cortex

Haines 2-11 = Primary Motor SMA FEF PMA Prefrontal Cortex Motor planning FEF PMA Motor planning Of voluntary action Prefrontal Cortex Processing sensory and memory info Decision making

Haines 2-24

MUSCLE TOPOGRAPHY IN PRIMARY MOTOR CORTEX

Haines 3-4 INTERNAL CAPSULE Anterior Limb Genu Posterior Limb

Haines 4-12 Thalmus medial to internal capsule

Haines 4-4 Posterior Limb contains: Decending cortical spinal fibers Ascending thalamocortical fibers Lentiform Nucleus = Putamen + Globus Pallidus Lentiform = lenticulate

Haines 4-1 Fibers from FEF

Haines 5-26 Rostral Midbrain Level Corticospinal Fibers Corticobulbar fibers – go to posterior limb of internal capsule Rostral Midbrain Level

Look at Wallerian degeneration P96-97

Haines 5-25 Red Nucleus Occulomotor Nucleus Nerve The corticospinal fibers are arranged topographically so that fibers to foot muscles are most lateral and those to the neck are most medial. Haines 5-25 Red Nucleus Corticospinal Fibers Occulomotor Nucleus Nerve Corticobulbar fibers Rostral Midbrain Level

Haines 5-23 Trochlear Nucleus – fibers from FEF via Premotor Area Corticospinal Fibers Corticobulbar fibers Caudal Midbrain Level

Haines 5-20 Trochlear nerve exit PAG Corticospinal and corticobulbar fibers mixed Rostral Pons Level

Haines 5-19 Trigeminal Main Motor Nucleus Reticular Form Supplies muscles of mastication Reticular Form Corticospinal and corticobulbar fibers mixed Rostral Pons Level

Haines 5-17 Abducens Nucleus Reticular Form Facial Nerve Fibers Corticospinal and corticobulbar fibers mixed Rostral Medulla Level

See slide 5-16 in text www.med.harvard.edu/AANLIB/cases/caseM/mr3

www.med.harvard.edu/AANLIB/cases/caseM/mr3 23

www.med.harvard.edu/AANLIB/cases/caseM/mr3 17 Do it yourself

Haines 5-12 Vestibular Nuclei MLF Reticular Form Pyramid Rostral Medulla Level

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

Blackboard 11 pyramidal tract - corticospinal/corticobulbar fibers    medullary reticular formation    vestibular nuclei and MLF    hypoglossal nucleus

Haines 5-2 Lateral Corticospinal tract Rubrospinal Tract Lateral Motor nuclei Lateral Vestibulospinal tract Medial Motor nuclei Lumbar Level

Haines 5-3 Lateral Corticospinal tract Rubrospinal Tract Anterior Corticospinal tract Medial Motor nuclei Thoracic Level

Haines 5-4 C7 Level