Cardiovascular endocrinology: atrial natriuretic peptide: 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.

Try it

Physiology · Cardiovascular endocrinology: atrial natriuretic peptide

Sample item

After a large intravenous saline load, atrial myocytes release a peptide that causes natriuresis and vasodilatation. Through which second messenger does it act?

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

The answer and the reasoning

B. Cyclic GMP, through a receptor with guanylyl cyclase activity

Atrial natriuretic peptide is released in response to atrial stretch and binds to a receptor with intrinsic particulate guanylyl cyclase activity, raising cyclic GMP. This causes afferent arteriolar dilatation, reduced sodium reabsorption in the collecting duct and inhibition of renin and aldosterone release. Nitric oxide also acts by cyclic GMP, but through the soluble enzyme.

Option by option

  • A. Tyrosine kinase activity, through an intrinsic receptor kinase

    Intrinsic tyrosine kinase receptors are used by insulin and growth factors.

  • B. Cyclic GMP, through a receptor with guanylyl cyclase activity (correct)

    Correct. ANP acts through cyclic GMP.

  • C. Inositol trisphosphate, through a Gq-coupled receptor

    The Gq and IP3 pathway is used by angiotensin II, which opposes ANP.

  • D. Cyclic AMP, through a Gs-coupled receptor

    Cyclic AMP is the messenger for hormones such as glucagon and ACTH, not ANP.

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 Physiology questions

Questions about this Physiology question

What is the answer to this Physiology question?

The best answer is B, Cyclic GMP, through a receptor with guanylyl cyclase activity. Atrial natriuretic peptide is released in response to atrial stretch and binds to a receptor with intrinsic particulate guanylyl cyclase activity, raising cyclic GMP.

Why is "Tyrosine kinase activity, through an intrinsic receptor kinase" not the answer?

Intrinsic tyrosine kinase receptors are used by insulin and growth factors.

Why is "Inositol trisphosphate, through a Gq-coupled receptor" not the answer?

The Gq and IP3 pathway is used by angiotensin II, which opposes ANP.

Why is "Cyclic AMP, through a Gs-coupled receptor" not the answer?

Cyclic AMP is the messenger for hormones such as glucagon and ACTH, not ANP.

What concept does this question test?

It tests Cardiovascular endocrinology: atrial natriuretic peptide in Physiology. This causes afferent arteriolar dilatation, reduced sodium reabsorption in the collecting duct and inhibition of renin and aldosterone release. Nitric oxide also acts by cyclic GMP, but through the soluble enzyme.

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 endocrinology: atrial natriuretic peptide?

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.