Blood and immunity: erythrocyte sedimentation: 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 · Blood and immunity: erythrocyte sedimentation

Sample item

A patient with chronic inflammation has a markedly raised erythrocyte sedimentation rate. Which change in the blood chiefly accounts for this?

ARaised albumin concentration reducing red cell aggregationBA high red cell count increasing the settling rateCIncreased negative surface charge on red cellsDRaised fibrinogen and globulins promoting rouleaux formation

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

The answer and the reasoning

D. Raised fibrinogen and globulins promoting rouleaux formation

Acute phase proteins, mainly fibrinogen and immunoglobulins, neutralise the negative surface charge (zeta potential) that keeps red cells apart. The cells then stack into rouleaux, which have a high weight-to-surface ratio and settle faster. Polycythaemia lowers the ESR and anaemia raises it.

Option by option

A. Raised albumin concentration reducing red cell aggregation
Albumin tends to keep the cells separated, so more albumin lowers the ESR.
B. A high red cell count increasing the settling rate
More red cells make the ESR lower, not higher, because crowding hinders settling.
C. Increased negative surface charge on red cells
A stronger negative charge makes the cells repel one another and slows sedimentation.
D. Raised fibrinogen and globulins promoting rouleaux formation (correct)
Correct. Fibrinogen and globulins favour rouleaux, which sediment faster.

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 Physiology question

What is the answer to this Physiology question?

The best answer is D, Raised fibrinogen and globulins promoting rouleaux formation. Acute phase proteins, mainly fibrinogen and immunoglobulins, neutralise the negative surface charge (zeta potential) that keeps red cells apart.

Why is "Raised albumin concentration reducing red cell aggregation" not the answer?

Albumin tends to keep the cells separated, so more albumin lowers the ESR.

Why is "A high red cell count increasing the settling rate" not the answer?

More red cells make the ESR lower, not higher, because crowding hinders settling.

Why is "Increased negative surface charge on red cells" not the answer?

A stronger negative charge makes the cells repel one another and slows sedimentation.

What concept does this question test?

It tests Blood and immunity: erythrocyte sedimentation in Physiology. The cells then stack into rouleaux, which have a high weight-to-surface ratio and settle faster. Polycythaemia lowers the ESR and anaemia raises 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 Blood and immunity: erythrocyte sedimentation?

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.