Head and neck: fibres passing through the ciliary ganglion: 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: fibres passing through the ciliary ganglion

Sample item

Fibres of three types pass through the ciliary ganglion, but only one type synapses in it. Which fibres traverse it without synapsing?

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

The answer and the reasoning

A. Postganglionic sympathetic fibres

Sympathetic postganglionic fibres from the internal carotid plexus and sensory fibres from the nasociliary nerve pass through the ganglion without synapsing. Only the parasympathetic fibres from the oculomotor nerve relay there. The sympathetic fibres supply the dilator pupillae and orbital vessels.

Option by option

  • A. Postganglionic sympathetic fibres (correct)

    Correct. They arrive from the carotid plexus and pass through to the short ciliary nerves.

  • B. Fibres from the abducens nerve

    The abducens nerve supplies only the lateral rectus and does not pass through the ganglion.

  • C. Preganglionic parasympathetic fibres

    These fibres are the ones that synapse in the ganglion.

  • D. Fibres from the trochlear nerve

    The trochlear nerve supplies only the superior oblique and does not pass through the ganglion.

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 A, Postganglionic sympathetic fibres. Sympathetic postganglionic fibres from the internal carotid plexus and sensory fibres from the nasociliary nerve pass through the ganglion without synapsing.

Why is "Fibres from the abducens nerve" not the answer?

The abducens nerve supplies only the lateral rectus and does not pass through the ganglion.

Why is "Preganglionic parasympathetic fibres" not the answer?

These fibres are the ones that synapse in the ganglion.

Why is "Fibres from the trochlear nerve" not the answer?

The trochlear nerve supplies only the superior oblique and does not pass through the ganglion.

What concept does this question test?

It tests Head and neck: fibres passing through the ciliary ganglion in Anatomy. Only the parasympathetic fibres from the oculomotor nerve relay there. The sympathetic fibres supply the dilator pupillae and orbital vessels.

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: fibres passing through the ciliary ganglion?

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.