Special senses: visual pathway: 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: visual pathway

Sample item

After a right anterior temporal lobectomy a patient reports loss of vision in the upper left quadrant of the visual field of both eyes. Which fibres have been interrupted?

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

The answer and the reasoning

D. Right Meyer loop of the optic radiation

Fibres from the inferior retina carry the superior visual field and loop forward into the temporal lobe as Meyer loop before reaching the lower bank of the calcarine sulcus. A right temporal lesion removes the left superior visual field in both eyes, giving a left superior quadrantanopia (pie in the sky). Parietal lesions give inferior quadrantanopia.

Option by option

  • A. Right parietal portion of the optic radiation

    A right parietal lesion would cause a left inferior quadrantanopia.

  • B. Right optic tract

    An optic tract lesion would cause a complete left homonymous hemianopia.

  • C. Left Meyer loop of the optic radiation

    A left-sided lesion would cause a right-sided field defect.

  • D. Right Meyer loop of the optic radiation (correct)

    Correct. Right Meyer loop carries the left upper field from both eyes.

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 D, Right Meyer loop of the optic radiation. Fibres from the inferior retina carry the superior visual field and loop forward into the temporal lobe as Meyer loop before reaching the lower bank of the calcarine sulcus.

Why is "Right parietal portion of the optic radiation" not the answer?

A right parietal lesion would cause a left inferior quadrantanopia.

Why is "Right optic tract" not the answer?

An optic tract lesion would cause a complete left homonymous hemianopia.

Why is "Left Meyer loop of the optic radiation" not the answer?

A left-sided lesion would cause a right-sided field defect.

What concept does this question test?

It tests Special senses: visual pathway in Physiology. A right temporal lesion removes the left superior visual field in both eyes, giving a left superior quadrantanopia (pie in the sky). Parietal lesions give inferior quadrantanopia.

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: visual pathway?

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.