1. UPPER AND LOWER MOTOR SYSTEMS
Lab 9
UPPER AND LOWER MOTOR SYSTEMS

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

3. 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

4. Haines 2-24

5. MUSCLE TOPOGRAPHY IN PRIMARY MOTOR CORTEX

7. Haines 3-4
INTERNAL CAPSULE
Anterior Limb
Genu
Posterior Limb

8. Haines 4-12
Thalmus medial to internal capsule

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

10. Haines 4-1
Fibers from FEF

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

13. Look at Wallerian degeneration
P96-97

14. 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

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

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

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

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

19. See slide 5-16 in text

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

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

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

23. 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

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

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

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

27. Haines 5-4
C7 Level