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PIXBRAIN HOME _ _ MOD 6 HOME _ _ previous _ _ FIGURE 6-11_ _ next _ _ I WANT TO _ _ _Once the motor commands have reached the spinal cord and movement has ensued, large diameter afferent fibers from muscle spindles and joint receptors measure the displacement that has actually taken place. This proprioceptive information is relayed to the spinocerebellum by the pathways shown here. This part of the cerebellum makes a comparison between the intended and actual movement. If there is a discrepancy between the two, corrective instructions are sent to the spinal cord. _ _ _The output of the intermediate region projects to the red nucleus by way of the superior cerebellar peduncle. Most of the fibers terminate there. Cells within the red nucleus then relay this information down to the cord in the rubrospinal tract. As Kingsley notes, some of the fibers in the superior cerebellar peduncle pass through the red nucleus and continue on, to terminate in the the thalamus. So the information concerned with the adjustment of ongoing motor activity is passed "up" to the cortex as well as "down" to the spinal cord. _ _ _The output of the vermis projects to the vestibular nuclei, and on to the cord in the vestibulospinal tracts. |