Anatomy and physiology of the eye: composition of aqueous humour: 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.

Try it

Ophthalmology · Anatomy and physiology of the eye: composition of aqueous humour

Sample item

Compared with plasma, aqueous humour contains a markedly higher concentration of which substance?

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

The answer and the reasoning

B. Ascorbate

Aqueous humour is actively enriched in ascorbate (vitamin C), which protects the lens and trabecular tissues against oxidative damage. Its protein, glucose and immunoglobulin content is much lower than in plasma because of the blood-aqueous barrier.

Option by option

  • A. Immunoglobulin G

    Immunoglobulins are largely excluded by the blood-aqueous barrier.

  • B. Ascorbate (correct)

    Correct. Ascorbate is actively secreted and reaches many times the plasma level.

  • C. Glucose

    Aqueous glucose is lower than plasma glucose.

  • D. Protein

    Aqueous protein is only a tiny fraction of plasma protein.

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.

More Ophthalmology questions

Questions about this Ophthalmology question

What is the answer to this Ophthalmology question?

The best answer is B, Ascorbate. Aqueous humour is actively enriched in ascorbate (vitamin C), which protects the lens and trabecular tissues against oxidative damage.

Why is "Immunoglobulin G" not the answer?

Immunoglobulins are largely excluded by the blood-aqueous barrier.

Why is "Glucose" not the answer?

Aqueous glucose is lower than plasma glucose.

Why is "Protein" not the answer?

Aqueous protein is only a tiny fraction of plasma protein.

What concept does this question test?

It tests Anatomy and physiology of the eye: composition of aqueous humour in Ophthalmology. Its protein, glucose and immunoglobulin content is much lower than in plasma because of the blood-aqueous barrier.

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: composition of aqueous humour?

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.