Reproduction: onset of menstruation: 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 menstruation

Sample item

Menstruation begins at the end of a non-conception cycle because:

AAn LH surge triggers the sloughing of the secretory endometriumBRising hCG from the corpus luteum causes endometrial breakdownCA rise in FSH directly erodes the endometrial stromaDFalling progesterone and oestrogen cause spiral arteriolar vasoconstriction, ischaemia and shedding of the functional layer

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

The answer and the reasoning

D. Falling progesterone and oestrogen cause spiral arteriolar vasoconstriction, ischaemia and shedding of the functional layer

Without implantation the corpus luteum regresses after about 14 days, so progesterone and oestrogen fall. Withdrawal of these hormones releases prostaglandin F2-alpha and causes vasospasm of the spiral arteries, causing ischaemia and necrosis. The functional layer sloughs off while the basal layer remains to regenerate it.

Option by option

A. An LH surge triggers the sloughing of the secretory endometrium
The LH surge triggers ovulation, and it comes before the luteal phase.
B. Rising hCG from the corpus luteum causes endometrial breakdown
hCG is produced after implantation and maintains the corpus luteum, so it prevents menstruation.
C. A rise in FSH directly erodes the endometrial stroma
FSH acts on follicles and has no direct erosive effect on endometrium.
D. Falling progesterone and oestrogen cause spiral arteriolar vasoconstriction, ischaemia and shedding of the functional layer (correct)
Hormone withdrawal produces vasoconstriction and ischaemic shedding of the functional layer.

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 D, Falling progesterone and oestrogen cause spiral arteriolar vasoconstriction, ischaemia and shedding of the functional layer. Without implantation the corpus luteum regresses after about 14 days, so progesterone and oestrogen fall.

Why is "An LH surge triggers the sloughing of the secretory endometrium" not the answer?

The LH surge triggers ovulation, and it comes before the luteal phase.

Why is "Rising hCG from the corpus luteum causes endometrial breakdown" not the answer?

hCG is produced after implantation and maintains the corpus luteum, so it prevents menstruation.

Why is "A rise in FSH directly erodes the endometrial stroma" not the answer?

FSH acts on follicles and has no direct erosive effect on endometrium.

What concept does this question test?

It tests Reproduction: onset of menstruation in Physiology. Withdrawal of these hormones releases prostaglandin F2-alpha and causes vasospasm of the spiral arteries, causing ischaemia and necrosis. The functional layer sloughs off while the basal layer remains to regenerate it.

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 menstruation?

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.