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14 Cards in this Set
- Front
- Back
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Mediated by 1a afferents innervatred by m spindles
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Myotatic (stretch) reflex
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1 grp of m excited (quads) while antagonist m (hamstrings) inhibited
Regulates muscle length |
Reciprocal inhibition
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Activated by grp 1b fibers from GTOs (not spindles)
Regulates tension Higher threshold than stretch reflex |
Inverse myotatic reflex
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Contracting muscle inhibits own muscle group by its own sensory input
Ie: posture |
Autogenic inhibition
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Polysynaptic reflex
Withdrawl reflex |
Flexor reflex
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During flexion of ipsilateral limb, contralateral limb inhibited
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Crossed extension reflex
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Reflexes used as a diagnostic tool
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1. Initial flaccid paralysis
2. Dev't of spasticity a. hypertonia b. hyperreflexia c. clasp-knife response d. clonus |
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Increases resistance to passive manipulation
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Hypertonia
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Exaggerated response to tendon-tap
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Hyperreflexia
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Increases resistance to displacement of a joint, suddenly collapses like the closing of a pocketknife
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Clasp-knife response
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A repetitive alternating contraction of flexors and extensors usually at distal joint
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Clonus
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alpha motor neurons vs. NMJ
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Alpha motor neurons: innervate extrafusal fibers
NMJ: neural innervation of skeletal m |
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During contraction, alpha and gamma motor neurons are activated
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Alpha-gamma coactivation
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Gamma loop
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gamma motor neurons not inhibited bc damage of descending pathways-->more excitable-->intrafusal fibers-->1a afferents-->alpha motor neurons-->extrafusal muscle fibers
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