Anatomy and physiology of the eye: oculocardiac reflex: practice question

A Ophthalmology 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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Ophthalmology · Anatomy and physiology of the eye: oculocardiac reflex

Sample item

A 7-year-old under general anaesthesia develops sudden bradycardia when the surgeon pulls on the medial rectus during squint surgery. What is the reflex arc?

AFacial afferent, glossopharyngeal efferentBVagal afferent, trigeminal efferentCOculomotor afferent, sympathetic efferentDTrigeminal afferent, vagal efferent

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

The answer and the reasoning

D. Trigeminal afferent, vagal efferent

In the oculocardiac reflex, traction on extraocular muscles or pressure on the globe sends impulses along the ophthalmic division of the trigeminal nerve to the brainstem, and the vagus slows the heart. Releasing traction usually settles it.

Option by option

A. Facial afferent, glossopharyngeal efferent
The facial and glossopharyngeal nerves are not part of this arc.
B. Vagal afferent, trigeminal efferent
The direction is reversed; the vagus is the efferent limb.
C. Oculomotor afferent, sympathetic efferent
The oculomotor nerve is motor to muscles and not the afferent limb of this reflex.
D. Trigeminal afferent, vagal efferent (correct)
Correct. The ophthalmic division of the trigeminal carries the afferent limb and the vagus the efferent limb.

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 Ophthalmology question

What is the answer to this Ophthalmology question?

The best answer is D, Trigeminal afferent, vagal efferent. In the oculocardiac reflex, traction on extraocular muscles or pressure on the globe sends impulses along the ophthalmic division of the trigeminal nerve to the brainstem, and the vagus slows the heart.

Why is "Facial afferent, glossopharyngeal efferent" not the answer?

The facial and glossopharyngeal nerves are not part of this arc.

Why is "Vagal afferent, trigeminal efferent" not the answer?

The direction is reversed; the vagus is the efferent limb.

Why is "Oculomotor afferent, sympathetic efferent" not the answer?

The oculomotor nerve is motor to muscles and not the afferent limb of this reflex.

What concept does this question test?

It tests Anatomy and physiology of the eye: oculocardiac reflex in Ophthalmology. Releasing traction usually settles it.

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 Anatomy and physiology of the eye: oculocardiac reflex?

Group the red eye by what to examine and what the pupil does. Then use the flashcards and the other Ophthalmology 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.