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7 Cards in this Set
- Front
- Back
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What happens to the stretch reflex if there is increased gamma motoneuron activity? What is the Golgi tendon reflex?
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Exaggerates the reflex
1. Active muscle contraction stimulates group 1b afferent fibers in the Golgi tendon organs a.- alpha motoneurons inhibited, which cause relaxation of the contracting muscle b.- Antagonistic muscles are activated |
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Describe the flexor withdrawal reflex.
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1. Pain stimulates group 11, 111, and 1V flexor reflex afferent fibers
2. Afferents synapse via interneurons to multiple motoneurons in the spinal cord 3. Ipsilateral side: Flexors are stimulated to contract and exyensors are inhibited, pulling the side away from the stimulus 4. Contralateral side: Flexors are inhibited and extensors are stimulated to maintain balance |
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What is the persistent neural activity that is left in the polysynaptic circuit of the flexor withdrawal reflex called?
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Afterdischarge
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What is the function of the afterdischarge?
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Prevents the muscle from relaxing for some time.
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What are Renshaw cells?
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Inhibitory inerneurons in the ventral horn of the spinal cord
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What are the pyramidal tracts?
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1. corticospinal tract
2. corticobulbar tract |
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What are the extrapyramidal tracts?
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1. Lateral vestibulospinal tract: Dieters nucleus--ipsilateral motoneurons and interneurons
2. Medullary reticulospinal tract: Medullary reticular formation--interneurons in the intermediate gray area. 3. Pontine reticulospinal tract: Nuclei in the pons--ventromedial spinal cord 4. Rubrospinal tract: Red nucleus-- lateral spinal cord interneurons 5. Tectospinal tract: Superior colliculus--cervical spinal cord |
