Assertion A: When a flexor muscle is excited, the probability of excitation decreases in the paired extensor muscle.
Reason R: The interneuron that excited a motor neuron to the flexor muscle also inhibited a motor neuron connected to the extensor muscle.
In the light of the above statements, choose the most appropriate answer from the options given below:
Reciprocal Innervation: Flexor and Extensor Muscles
This question concerns the physiological relationship between flexor and extensor muscles, a concept known as reciprocal innervation.
Analysis of Assertion A
Assertion A states that when a flexor muscle is excited, the probability of excitation decreases in the paired extensor muscle. This is a fundamental principle of motor control. For coordinated movement, when one set of muscles contracts (agonist, e.g., flexor), the opposing set (antagonist, e.g., extensor) must relax or be inhibited. Therefore, Assertion A is correct.
Analysis of Reason R
Reason R explains the mechanism behind this phenomenon. It states that the interneuron excited by the flexor muscle's pathway also inhibits the motor neuron connected to the extensor muscle. This specific neural circuit is called reciprocal inhibition. Sensory afferents (like Ia afferents from muscle spindles) or descending pathways activate excitatory interneurons to the agonist's motor neurons and inhibitory interneurons (often Ia inhibitory interneurons) to the antagonist's motor neurons. Thus, Reason R accurately describes the neural basis for reciprocal innervation and is correct.
Evaluating the Explanation
Reason R provides the direct physiological mechanism (inhibition of the extensor motor neuron via an interneuron) that causes the effect described in Assertion A (decreased excitation probability in the extensor muscle). Therefore, Reason R is the correct explanation of Assertion A.
Conclusion
Both Assertion A and Reason R are correct statements, and Reason R provides the accurate explanation for Assertion A.
Final Answer Choice
Based on the analysis, the most appropriate choice is that both A and R are correct, and R is the correct explanation of A.
Similar Questions
- Which of the following provides a quantitative measure of the differences between scores in a distribution and describes the degree to which the scores are spread out or clustered together?
- Which of the following refers to the peakedness or flatness of a frequency distribution as compared to the normal distribution?
- Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: There is decreased effect of a drug when it is taken repeatedly.
Reason R: Conditioned compensatory response is not triggered when drug is taken in usual circumstances.
In the light of the above statements, choose the most appropriate answer from the options given below: - Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: There is diminishing responsiveness of sensory systems to prolonged stimulation, as and when a person adopts to new environmental condition.
Reason R: The unchanging stimulation usually shifts into the background of awareness of the person.
In the light of the above statements, choose the most appropriate answer from the options given below: - Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Happy mood can increase creativity.
Reason R: Nigotiators who are in a good mood adopt more cooperative strategies and expect better outcomes.
In the light of the above statements, choose the most appropriate answer from the options given below: - Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Older, more experienced individuals can sometimes outperform younger ones on cognitive tasks ranging from scientific research to chess.
Reason R: Fluid intelligence seems to increase slowly with age but crystallized intelligence decreases.
In the light of the above statements, choose the most appropriate answer from the options given below: - Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: People who expect to handle stress often actually do and are happy and satisfied in life.
Reason R: The likelihood that a given behaviour will occur in a specific situation does not depend on individuals expectancies concerning the outcome of behaviour.
In the light of the above statements, choose the most appropriate answer from the options given below: - Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: The IQ scores of the children of mothers who are exposed to teratogens are found to be low.
Reason R: The use of drugs, alcohol consumption and smoking by mothers lead to central nervous system dysfunction in children.
In the light of the above statements, choose the most appropriate answer from the options given below: - Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Maternal depression is linked to preterm birth and slower prenatal growth rates.
Reason R: Mothers who are depressed have decreased cortisol levels.
In the light of the above statements, choose the most appropriate answer from the options given below: - Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: People with bulimia nervosa try to compensate or undo its effects by vomiting or using laxatives.
Reason R: Compensatory behaviours temporarily relieve uncomfortable feeling of fullness, anxiety and disgust.
In the light of the above statements, choose the most appropriate answer from the options given below:
Important Questions from Miscellaneous
- Which of the following scheduler/schedulers is/are also called CPU scheduler ?
(A). Short Term Scheduler
(B). Long Term Scheduler
(C). Medium Term Scheduler
(D). Asymmetric Scheduler
Choose the correct answer from the options given below: - A situation where two or more processes are blocked, waiting for resources held by each other is called:
- External fragmentation occurs ________.
- Which disk scheduling algorithm looks for the track closest to the current head position?
- Which CPU scheduling algorithm prefers the process with the shortest burst time?
