BRAIN
SPINAL CORD
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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It is ipsilateral.
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It causes contraction of the agonist muscle.
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It causes an inhibitory arc in the antagonist muscle.
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It causes an inhibitory arc in the agonist muscle.
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Detailed explanation-1: -Answer and Explanation: Stretch reflex is b) important in regulating muscle length. It is not an example of a polysynaptic reflex as option (a) suggests but rather it is a monosynaptic reflex, a simple reflex involving only one synapse between the sensory and motor neuron.
Detailed explanation-2: -In the knee-jerk reflex this corresponds to the quadriceps muscle. Simultaneously, the stretch receptor synapses on an interneuron that inhibits the antagonistic muscle, which in this case is a flexor muscle, the semitendinosus.
Detailed explanation-3: -The simplest of these reflex arcs entails the response to muscle stretch, which provides direct excitatory feedback to the motor neurons innervating the muscle that has been stretched (Figure 16.9).