Reproduction: temperature and spermatogenesis: 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: temperature and spermatogenesis

Sample item

A man with untreated bilateral undescended testes has impaired spermatogenesis in adulthood. Which factor is chiefly responsible?

AAbsence of Sertoli cellsBFailure of testosterone synthesis by Leydig cellsCHigher temperature in the abdomen than in the scrotumDLack of FSH secretion

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

The answer and the reasoning

C. Higher temperature in the abdomen than in the scrotum

Spermatogenesis needs a temperature a few degrees below core body temperature, which the scrotum maintains through the pampiniform plexus and the dartos and cremaster muscles. Testes kept in the abdomen are too warm and the germ cells degenerate, though Leydig cell function is relatively preserved.

Option by option

A. Absence of Sertoli cells
Sertoli cells are present, though they are damaged by heat.
B. Failure of testosterone synthesis by Leydig cells
Leydig cells are relatively preserved, so testosterone is often near normal.
C. Higher temperature in the abdomen than in the scrotum (correct)
Correct. Core temperature impairs spermatogenesis in an undescended testis.
D. Lack of FSH secretion
FSH secretion is normal and does not explain the problem.

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, Higher temperature in the abdomen than in the scrotum. Spermatogenesis needs a temperature a few degrees below core body temperature, which the scrotum maintains through the pampiniform plexus and the dartos and cremaster muscles.

Why is "Absence of Sertoli cells" not the answer?

Sertoli cells are present, though they are damaged by heat.

Why is "Failure of testosterone synthesis by Leydig cells" not the answer?

Leydig cells are relatively preserved, so testosterone is often near normal.

Why is "Lack of FSH secretion" not the answer?

FSH secretion is normal and does not explain the problem.

What concept does this question test?

It tests Reproduction: temperature and spermatogenesis in Physiology. Testes kept in the abdomen are too warm and the germ cells degenerate, though Leydig cell function is relatively preserved.

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: temperature and spermatogenesis?

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.