Reproduction: milk ejection reflex: 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: milk ejection reflex

Sample item

A breastfeeding mother is suddenly distressed by a loud argument. Her infant continues to suck, but milk flow stops although her milk production remains normal. What is the mechanism?

AProlactin-inhibiting factor blocks the alveolar cellsBA rise in progesterone blocks ductal contractionCStress inhibits oxytocin release, so myoepithelial cells do not contractDA fall in prolactin ends milk synthesis immediately

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

The answer and the reasoning

C. Stress inhibits oxytocin release, so myoepithelial cells do not contract

Suckling triggers a neuroendocrine reflex that releases oxytocin from the posterior pituitary, causing myoepithelial contraction and milk ejection. Emotional stress inhibits oxytocin release centrally, so the let-down fails while milk synthesis (prolactin-dependent) continues.

Option by option

A. Prolactin-inhibiting factor blocks the alveolar cells
Dopamine, the prolactin-inhibiting factor, affects synthesis, not let-down.
B. A rise in progesterone blocks ductal contraction
Progesterone is low after delivery, and does not mediate the reflex.
C. Stress inhibits oxytocin release, so myoepithelial cells do not contract (correct)
Correct. Reduced oxytocin prevents milk ejection.
D. A fall in prolactin ends milk synthesis immediately
Prolactin governs synthesis over a longer timescale, and does not control ejection within seconds.

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, Stress inhibits oxytocin release, so myoepithelial cells do not contract. Suckling triggers a neuroendocrine reflex that releases oxytocin from the posterior pituitary, causing myoepithelial contraction and milk ejection.

Why is "Prolactin-inhibiting factor blocks the alveolar cells" not the answer?

Dopamine, the prolactin-inhibiting factor, affects synthesis, not let-down.

Why is "A rise in progesterone blocks ductal contraction" not the answer?

Progesterone is low after delivery, and does not mediate the reflex.

Why is "A fall in prolactin ends milk synthesis immediately" not the answer?

Prolactin governs synthesis over a longer timescale, and does not control ejection within seconds.

What concept does this question test?

It tests Reproduction: milk ejection reflex in Physiology. Emotional stress inhibits oxytocin release centrally, so the let-down fails while milk synthesis (prolactin-dependent) continues.

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: milk ejection reflex?

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.