Question
What are the outcomes of experimental muscle spindle sectioning in frogs?
| A. |
Voluntary action and stretch reflex are both present
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| B. |
Voluntary action is lost but stretch reflex is present
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| C. |
Both voluntary action and stretch reflex are lost
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| D. |
Voluntary action is present, but stretch reflex is lost
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Show Answer
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Correct Answer � C
Explanation
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The muscle spindle is a sensory receptor located within the muscle that is responsible for detecting changes in muscle length and initiating the stretch reflex. Experimental sectioning of the muscle spindle in frogs would result in the loss of this sensory feedback mechanism.
As a consequence, both voluntary actions involving muscle contraction and the stretch reflex, which relies on muscle spindle input, would be lost.
Reasons for ruling out other options are-
A. Voluntary action and stretch reflex are both present: This option is incorrect because sectioning the muscle spindle would disrupt the stretch reflex, resulting in its absence.
B. Voluntary action is lost but stretch reflex is present: This option is incorrect because, while sectioning the muscle spindle would eliminate the stretch reflex, voluntary action would also be lost due to the disruption of sensory feedback from the muscle spindle.
D. Voluntary action is present, but stretch reflex is lost: This option is incorrect because if the stretch reflex is lost, it indicates that the sensory feedback mechanism from the muscle spindle is disrupted, which would likely affect voluntary action as well.
