Reproduction: menstruation mechanism: 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: menstruation mechanism

Sample item

A woman with secondary amenorrhoea is given oral progestogen for 10 days. Bleeding occurs two days after stopping. What is the immediate mechanism?

AA surge in FSH induces endometrial breakdownBA rising progesterone level causes endometrial thinningCHormone withdrawal causes prostaglandin-mediated vasoconstriction of spiral arteries and ischaemic shedding of the functional layerDA rise in LH triggers bleeding

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

The answer and the reasoning

C. Hormone withdrawal causes prostaglandin-mediated vasoconstriction of spiral arteries and ischaemic shedding of the functional layer

A withdrawal bleed after a progestogen challenge indicates adequate endogenous oestrogen priming of the endometrium. Falling progesterone leads to release of prostaglandin F2-alpha and matrix metalloproteinases, spiral artery vasospasm, ischaemia and desquamation of the functional layer.

Option by option

A. A surge in FSH induces endometrial breakdown
FSH acts on the ovary and not directly on the endometrium.
B. A rising progesterone level causes endometrial thinning
Progesterone is falling, not rising, at the time of bleeding.
C. Hormone withdrawal causes prostaglandin-mediated vasoconstriction of spiral arteries and ischaemic shedding of the functional layer (correct)
Correct. Progesterone withdrawal triggers spiral artery ischaemia and shedding.
D. A rise in LH triggers bleeding
LH does not directly act on the endometrium to cause bleeding.

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 C, Hormone withdrawal causes prostaglandin-mediated vasoconstriction of spiral arteries and ischaemic shedding of the functional layer. A withdrawal bleed after a progestogen challenge indicates adequate endogenous oestrogen priming of the endometrium.

Why is "A surge in FSH induces endometrial breakdown" not the answer?

FSH acts on the ovary and not directly on the endometrium.

Why is "A rising progesterone level causes endometrial thinning" not the answer?

Progesterone is falling, not rising, at the time of bleeding.

Why is "A rise in LH triggers bleeding" not the answer?

LH does not directly act on the endometrium to cause bleeding.

What concept does this question test?

It tests Reproduction: menstruation mechanism in Physiology. Falling progesterone leads to release of prostaglandin F2-alpha and matrix metalloproteinases, spiral artery vasospasm, ischaemia and desquamation of the functional layer.

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: menstruation mechanism?

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.