Reproduction: onset of parturition: 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 · Reproduction: onset of parturition

Sample item

Near term, the uterus becomes much more sensitive to oxytocin. Which change in the myometrium contributes?

AIncreased oxytocin receptors and gap junctions under rising oestrogen influenceBReduced myometrial smooth muscle massCIncreased progesterone receptor signalling that raises excitabilityDLoss of calcium channels from smooth muscle cells

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

The answer and the reasoning

A. Increased oxytocin receptors and gap junctions under rising oestrogen influence

Towards term the myometrium expresses more oxytocin receptors and forms more gap junctions, so it responds strongly to oxytocin and contracts in a coordinated way. Oestrogen promotes these changes, supporting labour.

Option by option

A. Increased oxytocin receptors and gap junctions under rising oestrogen influence (correct)
Correct. More oxytocin receptors and gap junctions sensitise and coordinate the myometrium.
B. Reduced myometrial smooth muscle mass
Muscle mass increases in pregnancy and does not fall to increase sensitivity.
C. Increased progesterone receptor signalling that raises excitability
Progesterone keeps the uterus quiescent and does not raise excitability.
D. Loss of calcium channels from smooth muscle cells
Contraction needs calcium entry, so losing calcium channels would reduce contractility.

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.

Questions about this Physiology question

What is the answer to this Physiology question?

The best answer is A, Increased oxytocin receptors and gap junctions under rising oestrogen influence. Towards term the myometrium expresses more oxytocin receptors and forms more gap junctions, so it responds strongly to oxytocin and contracts in a coordinated way.

Why is "Reduced myometrial smooth muscle mass" not the answer?

Muscle mass increases in pregnancy and does not fall to increase sensitivity.

Why is "Increased progesterone receptor signalling that raises excitability" not the answer?

Progesterone keeps the uterus quiescent and does not raise excitability.

Why is "Loss of calcium channels from smooth muscle cells" not the answer?

Contraction needs calcium entry, so losing calcium channels would reduce contractility.

What concept does this question test?

It tests Reproduction: onset of parturition in Physiology. Oestrogen promotes these changes, supporting labour.

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 Reproduction: onset of parturition?

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.