Lateral tracts decussation is crossing over some are

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Unformatted text preview: act – extrapyramidal neurons Pyramidal tracts Cut across in the medulla Some might be ipsilateral in the anterior pyramidal tract Fine control of voluntary movement of the distal extremities (forearms, hands, fingers) Upper motor neurons originate in primary motor cortex Upper lower one synapse (monosynaptic to effector, which is muscle) Axons terminate in ventral horn; collaterals go to brainstem nuclei Direct input to motor neurons (some through interneurons) Most cross to contralateral side in the medullary pyramids (lateral tracts) Decussation is crossing over Some are uncrossed until the appropriate level of the spinal cord (anterior tract) Extrapyramidal Tracts All motor pathways outside of the pyramidal system; carry motor information; processed differently than in pyramidal Indirect connections for the brain and spinal cord motor neurons; connect interneurons in the brainstem with medial spinal interneurons; they do not synapse directly with motor neurons (polysynaptic to effector) Supportive voluntary movement of the trunk, ne...
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