Cardiovascular physiology: jugular venous pulse: 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 · Cardiovascular physiology: jugular venous pulse

Sample item

A patient with complete heart block has intermittent large, brisk waves in the neck veins. These 'cannon a waves' occur because:

AThe ventricle contracts and the tricuspid valve bulges back into the atriumBThe atrium contracts against a closed tricuspid valve when atrial and ventricular beats coincideCThe right atrium fills during ventricular systoleDBlood flows rapidly from the atrium into the ventricle in early diastole

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

The answer and the reasoning

B. The atrium contracts against a closed tricuspid valve when atrial and ventricular beats coincide

In complete heart block the atria and ventricles beat independently. When the atrium contracts at a time when the tricuspid valve is shut by ventricular systole, blood is forced back into the great veins, giving a cannon a wave. Absent a waves are seen in atrial fibrillation.

Option by option

A. The ventricle contracts and the tricuspid valve bulges back into the atrium
Tricuspid bulging during systole produces the c wave, which is small.
B. The atrium contracts against a closed tricuspid valve when atrial and ventricular beats coincide (correct)
Correct. Atrial contraction against a closed tricuspid valve produces the tall a wave.
C. The right atrium fills during ventricular systole
Atrial filling in systole produces the v wave.
D. Blood flows rapidly from the atrium into the ventricle in early diastole
Rapid early filling corresponds to the y descent, not a cannon wave.

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 B, The atrium contracts against a closed tricuspid valve when atrial and ventricular beats coincide. In complete heart block the atria and ventricles beat independently.

Why is "The ventricle contracts and the tricuspid valve bulges back into the…" not the answer?

Tricuspid bulging during systole produces the c wave, which is small.

Why is "The right atrium fills during ventricular systole" not the answer?

Atrial filling in systole produces the v wave.

Why is "Blood flows rapidly from the atrium into the ventricle in early diast…" not the answer?

Rapid early filling corresponds to the y descent, not a cannon wave.

What concept does this question test?

It tests Cardiovascular physiology: jugular venous pulse in Physiology. When the atrium contracts at a time when the tricuspid valve is shut by ventricular systole, blood is forced back into the great veins, giving a cannon a wave. Absent a waves are seen in atrial fibrillation.

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 Cardiovascular physiology: jugular venous pulse?

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.