Special senses: vestibular caloric test: 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 · Special senses: vestibular caloric test

Sample item

During caloric testing of a conscious healthy patient, cold water is irrigated into the right external ear. What eye movement follows?

ANo eye movementBVertical nystagmus with a fast phase upwardCSlow drift to the right with a fast corrective phase to the leftDSlow drift to the left with a fast corrective phase to the right

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

The answer and the reasoning

C. Slow drift to the right with a fast corrective phase to the left

Cold irrigation reduces firing of the right horizontal canal, mimicking head turning to the left, so the vestibulo-ocular reflex drives a slow phase toward the right. The cortex corrects with a fast phase to the left. The mnemonic COWS (cold opposite, warm same) names the fast phase.

Option by option

A. No eye movement
A normal vestibular system responds with nystagmus.
B. Vertical nystagmus with a fast phase upward
Caloric stimulation of the horizontal canal evokes horizontal nystagmus.
C. Slow drift to the right with a fast corrective phase to the left (correct)
Correct. Slow phase toward the cold ear with a fast phase away from it.
D. Slow drift to the left with a fast corrective phase to the right
This describes warm water in the right ear.

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, Slow drift to the right with a fast corrective phase to the left. Cold irrigation reduces firing of the right horizontal canal, mimicking head turning to the left, so the vestibulo-ocular reflex drives a slow phase toward the right.

Why is "No eye movement" not the answer?

A normal vestibular system responds with nystagmus.

Why is "Vertical nystagmus with a fast phase upward" not the answer?

Caloric stimulation of the horizontal canal evokes horizontal nystagmus.

Why is "Slow drift to the left with a fast corrective phase to the right" not the answer?

This describes warm water in the right ear.

What concept does this question test?

It tests Special senses: vestibular caloric test in Physiology. The cortex corrects with a fast phase to the left. The mnemonic COWS (cold opposite, warm same) names the fast phase.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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 Special senses: vestibular caloric test?

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.