Neurophysiology - Motor System

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Reflex Arc
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Terms in this set (21)
Inverse Stretch Reflexreflex that occurs when tension reaches certain amount and contraction suddenly ceases, muscle relaxes; Golgi tendon organ (GTO) =receptorGolgi Tendon Organhas 1b afferent fibers that are INHIBITORY to α motor neurons; located within muscle tendon in SERIES with muscle (stimulated by stretch or by contraction of muscle)Withdrawal Reflexelicited by noxious and usually painful stimuli; protective, preempts spinal pathways from any other reflex activity; excites flexors, inhibits extensors; "local sign"Reciprocal Innervationexcitation of one group of muscles often associated with inhibition of another group of musclesCross Extensor Reflexshortly after stimulus elicits flexor reflex in one limb, opposite limb begins to extend (example of reciprocal innervation); important reflex as automatic adjustment to weight bearingPrimary Motor Cortexmotor homunculus; receives sensory input; controls more skilled movementsSupplementary Motor Arealocated anterior to primary motor cortex; controls less defined functionsPremotor Cortex (Motor Association Area)found on precentral gyrus; capable of controlling coordinated movements involving many muscles simultaneouslyBrainstem (wRt motor system)structure that is tonus generator for posture; controls vestibular and neck reflexes (important for body orientation)Basal Ganglia (wRt motor system)structure that has a role in learned patterns for behavior (e.g. writing) and in helping with "INITIATION" and carrying out of movementCerebellum (wRt motor system)best informed of all motor structures; coordinates and enables smooth muscular activity