Cardiovascular reflexes: 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 · Cardiovascular reflexes

Sample item

During carotid sinus massage a 60-year-old man's heart rate and blood pressure fall. Which nerve carries the afferent signal from the carotid sinus to the brainstem?

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

The answer and the reasoning

C. Glossopharyngeal nerve

Stretch of the carotid sinus is sensed by baroreceptors whose afferents run in the sinus nerve of Hering, a branch of the glossopharyngeal nerve, to the nucleus tractus solitarius. The reflex raises vagal tone and lowers sympathetic outflow, so heart rate and pressure fall.

Option by option

  • A. Facial nerve

    The facial nerve supplies facial muscles and taste and plays no part in the baroreceptor reflex.

  • B. Vagus nerve

    The vagus carries afferents from the aortic arch baroreceptors and is the efferent limb to the heart, but not the carotid sinus afferent.

  • C. Glossopharyngeal nerve (correct)

    Correct. The carotid sinus nerve is a branch of the glossopharyngeal nerve.

  • D. Hypoglossal nerve

    The hypoglossal nerve is purely motor to the tongue muscles.

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.

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Questions about this Physiology question

What is the answer to this Physiology question?

The best answer is C, Glossopharyngeal nerve. Stretch of the carotid sinus is sensed by baroreceptors whose afferents run in the sinus nerve of Hering, a branch of the glossopharyngeal nerve, to the nucleus tractus solitarius.

Why is "Facial nerve" not the answer?

The facial nerve supplies facial muscles and taste and plays no part in the baroreceptor reflex.

Why is "Vagus nerve" not the answer?

The vagus carries afferents from the aortic arch baroreceptors and is the efferent limb to the heart, but not the carotid sinus afferent.

Why is "Hypoglossal nerve" not the answer?

The hypoglossal nerve is purely motor to the tongue muscles.

What concept does this question test?

It tests Cardiovascular reflexes in Physiology. The reflex raises vagal tone and lowers sympathetic outflow, so heart rate and pressure fall.

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 Cardiovascular reflexes?

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.