Cell injury: reversible injury: practice question

A Pathology 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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Pathology · Cell injury: reversible injury

Sample item

A hepatocyte exposed briefly to a mitochondrial toxin appears swollen and pale, with small cytoplasmic vacuoles, and recovers when the toxin is removed. Which primary biochemical event best explains the swelling?

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

The answer and the reasoning

A. Failure of the Na+/K+ ATPase pump after ATP depletion, so sodium and water enter the cell

Mitochondrial injury reduces oxidative phosphorylation and ATP. The membrane sodium pump fails, sodium and water accumulate, and the cell swells (hydropic change); this is still reversible. Calcium overload, lysosomal rupture and caspase activation belong to irreversible injury or apoptosis.

Option by option

  • A. Failure of the Na+/K+ ATPase pump after ATP depletion, so sodium and water enter the cell (correct)

    Correct. ATP depletion stops the sodium pump, producing reversible cellular swelling.

  • B. Rupture of lysosomal membranes releasing hydrolytic enzymes

    Lysosomal rupture and enzyme leakage are late events in irreversible injury and necrosis.

  • C. Activation of caspase-9 through cytochrome c release

    Caspase-9 activation drives apoptosis and does not produce simple reversible swelling.

  • D. Massive calcium influx activating phospholipases and endonucleases

    Large calcium influx with enzyme activation marks irreversibility rather than early swelling.

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.

More Pathology questions

Questions about this Pathology question

What is the answer to this Pathology question?

The best answer is A, Failure of the Na+/K+ ATPase pump after ATP depletion, so sodium and water enter the cell. Mitochondrial injury reduces oxidative phosphorylation and ATP.

Why is "Rupture of lysosomal membranes releasing hydrolytic enzymes" not the answer?

Lysosomal rupture and enzyme leakage are late events in irreversible injury and necrosis.

Why is "Activation of caspase-9 through cytochrome c release" not the answer?

Caspase-9 activation drives apoptosis and does not produce simple reversible swelling.

Why is "Massive calcium influx activating phospholipases and endonucleases" not the answer?

Large calcium influx with enzyme activation marks irreversibility rather than early swelling.

What concept does this question test?

It tests Cell injury: reversible injury in Pathology. The membrane sodium pump fails, sodium and water accumulate, and the cell swells (hydropic change); this is still reversible. Calcium overload, lysosomal rupture and caspase activation belong to irreversible injury or apoptosis.

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 Cell injury: reversible injury?

Learn each disease as a bundle: cause, key histology, markers, and the clinical hallmark. Then use the flashcards and the other Pathology 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.