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In spinal cord pathways ascend and descend in columns

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Unformatted text preview: 462 ©FK ‘08 Spinal Cord: Pathways • In spinal cord, pathways ascend and descend in ‘columns’ • afferent pathways: somatossensory pathways – From skin/joint receptors • Medial lemniscus-dorsal column pathway – From pain / temperature receptors • Spinothalamic tract • efferent pathways – Corticospinal tract – Reticulospinal tract rubro spinal tract afferent pathwaysconsists on a chain of three neurons the first is the receptor neuron primary sensory nueroin to secondary neuron in grey matter to to tetiary neuron in the thalamus leading up to the grey matter. -corticolspinal-the sensory pathway for all voluntary mvmnt info--the neuron start in motor coretx and downt he sponal cord that synapses with motor neuron that innervates the mus reticulaspinal--in brain stem and responsibible fro rapid postueral adjustements Spinal Motor Neurons • Cell bodies of motor neurons innervating individual muscles are clustered in motor nuclei (motor neuron pools) – form longitudinal columns spanning 1-4 spinal segments. – follow two anatomical / functional rules • proximal – distal rule • flexor - extensor rule KNES 462 Functional grouping of motor tracts • Functional grouping of motor nuclei of spinal cord: – lateral positions: motor neurons innervate distal muscles. – medial positions: motor neurons innervating axial muscles of neck / back. fibers that innervate the distal part rums laterally to the proximal limbs fibers innervating flexor muscles run ventrally to the ones innervateing the extensors the nervous system keeps it pathways in an an orderly arrangement....
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This document was uploaded on 03/19/2014 for the course KNES 462 at Maryland.

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