Respiratory physiology: 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 · Respiratory physiology

Sample item

Why does carbon monoxide poisoning impair oxygen delivery?

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

The answer and the reasoning

A. It occupies haemoglobin and shifts remaining binding left

Carbon monoxide binds haemoglobin with high affinity, reducing oxygen content and impairing unloading from remaining sites despite potentially normal pulse oximetry.

Option by option

  • A. It occupies haemoglobin and shifts remaining binding left (correct)

    Correct: binding reduces content and tissue unloading.

  • B. It dissolves alveoli

    Alveoli are not dissolved.

  • C. It increases plasma bicarbonate

    Bicarbonate is not the main mechanism.

  • D. It blocks all airway smooth muscle

    Airway smooth muscle is not the target.

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 Physiology questions

Questions about this Physiology question

What is the answer to this Physiology question?

The best answer is A, It occupies haemoglobin and shifts remaining binding left. Carbon monoxide binds haemoglobin with high affinity, reducing oxygen content and impairing unloading from remaining sites despite potentially normal pulse oximetry.

Why is "It dissolves alveoli" not the answer?

Alveoli are not dissolved.

Why is "It increases plasma bicarbonate" not the answer?

Bicarbonate is not the main mechanism.

Why is "It blocks all airway smooth muscle" not the answer?

Airway smooth muscle is not the target.

What concept does this question test?

It tests Respiratory physiology in Physiology. The correct option holds because: Correct: binding reduces content and tissue unloading.

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 Respiratory physiology?

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.