Nerve and muscle: recurrent inhibition by Renshaw cells: practice question

A Physiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Physiology · Nerve and muscle: recurrent inhibition by Renshaw cells

Sample item

Collaterals of alpha motor neurone axons excite spinal interneurones that release glycine onto the same motor neurone and its neighbours. Which cells are these?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Renshaw cells

Renshaw cells are excited by collaterals of alpha motor neurones and inhibit those neurones, giving negative feedback that limits firing frequency (recurrent inhibition). Ia inhibitory interneurones instead mediate reciprocal inhibition of antagonist muscles.

Option by option

  • A. Renshaw cells (correct)

    Correct. Renshaw cells provide recurrent feedback inhibition.

  • B. Gamma motor neurones

    Gamma motor neurones supply the intrafusal fibres.

  • C. Golgi tendon organs

    Golgi tendon organs are sensory receptors, not interneurones.

  • D. Ia inhibitory interneurones

    Ia inhibitory interneurones inhibit antagonist motor neurones, not the same one.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this Physiology question

What is the answer to this Physiology question?

The best answer is A, Renshaw cells. Renshaw cells are excited by collaterals of alpha motor neurones and inhibit those neurones, giving negative feedback that limits firing frequency (recurrent inhibition).

Why is "Gamma motor neurones" not the answer?

Gamma motor neurones supply the intrafusal fibres.

Why is "Golgi tendon organs" not the answer?

Golgi tendon organs are sensory receptors, not interneurones.

Why is "Ia inhibitory interneurones" not the answer?

Ia inhibitory interneurones inhibit antagonist motor neurones, not the same one.

What concept does this question test?

It tests Nerve and muscle: recurrent inhibition by Renshaw cells in Physiology. Ia inhibitory interneurones instead mediate reciprocal inhibition of antagonist muscles.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Nerve and muscle: recurrent inhibition by Renshaw cells?

For each system, sketch the key graph (pressure–volume loop, oxygen dissociation curve, nephron handling) and explain it aloud. Then use the flashcards and the other Physiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.