Head and neck: annulus of Zinn: practice question

A Anatomy 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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Anatomy · Head and neck: annulus of Zinn

Sample item

In a patient with an orbital apex mass, which structure normally passes through the superior orbital fissure outside the common tendinous ring?

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

The answer and the reasoning

C. Trochlear nerve

The trochlear, frontal and lacrimal nerves and the superior ophthalmic vein enter the orbit outside the common tendinous ring. The oculomotor nerve with its two divisions, the nasociliary nerve and the abducens nerve pass through the ring. The optic nerve passes through the optic canal within it.

Option by option

  • A. Nasociliary nerve

    The nasociliary nerve passes through the ring between the divisions of the oculomotor nerve.

  • B. Inferior division of the oculomotor nerve

    Both divisions of the oculomotor nerve pass through the common tendinous ring.

  • C. Trochlear nerve (correct)

    Correct. The trochlear nerve lies outside the ring, above it.

  • D. Abducens nerve

    The abducens nerve passes through the common tendinous ring.

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 Anatomy question

What is the answer to this Anatomy question?

The best answer is C, Trochlear nerve. The trochlear, frontal and lacrimal nerves and the superior ophthalmic vein enter the orbit outside the common tendinous ring.

Why is "Nasociliary nerve" not the answer?

The nasociliary nerve passes through the ring between the divisions of the oculomotor nerve.

Why is "Inferior division of the oculomotor nerve" not the answer?

Both divisions of the oculomotor nerve pass through the common tendinous ring.

Why is "Abducens nerve" not the answer?

The abducens nerve passes through the common tendinous ring.

What concept does this question test?

It tests Head and neck: annulus of Zinn in Anatomy. The oculomotor nerve with its two divisions, the nasociliary nerve and the abducens nerve pass through the ring. The optic nerve passes through the optic canal within it.

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 Head and neck: annulus of Zinn?

Learn every nerve by its route, its muscles and what a lesion looks like at the bedside. That one habit answers a large share of questions. Then use the flashcards and the other Anatomy 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.