Endocrine pancreas: glucagon: 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 · Endocrine pancreas: glucagon

Sample item

A malnourished alcoholic patient with severe hypoglycaemia does not respond to intramuscular glucagon. What is the most likely reason?

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

The answer and the reasoning

D. Hepatic glycogen stores are depleted, so glycogenolysis cannot raise glucose

Glucagon raises blood glucose mainly through hepatic glycogenolysis and gluconeogenesis, acting through cyclic AMP. In starvation or after heavy alcohol intake liver glycogen is exhausted and gluconeogenesis is impaired, so glucagon is ineffective, and intravenous glucose is needed. Muscle lacks glucose-6-phosphatase and glucagon receptors, so it cannot supply glucose to the blood.

Option by option

  • A. Alcohol irreversibly inactivates circulating glucagon

    Alcohol impairs gluconeogenesis by raising the NADH to NAD ratio, but it does not inactivate glucagon.

  • B. Glucagon acts mainly on adipose tissue rather than the liver

    The liver is the main target of glucagon; its lipolytic action is minor and does not raise blood glucose.

  • C. Glucagon receptors are absent in the liver

    The liver is the main site of glucagon receptors.

  • D. Hepatic glycogen stores are depleted, so glycogenolysis cannot raise glucose (correct)

    Correct. Without hepatic glycogen, glucagon has nothing to mobilise.

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, Hepatic glycogen stores are depleted, so glycogenolysis cannot raise glucose. Glucagon raises blood glucose mainly through hepatic glycogenolysis and gluconeogenesis, acting through cyclic AMP.

Why is "Alcohol irreversibly inactivates circulating glucagon" not the answer?

Alcohol impairs gluconeogenesis by raising the NADH to NAD ratio, but it does not inactivate glucagon.

Why is "Glucagon acts mainly on adipose tissue rather than the liver" not the answer?

The liver is the main target of glucagon; its lipolytic action is minor and does not raise blood glucose.

Why is "Glucagon receptors are absent in the liver" not the answer?

The liver is the main site of glucagon receptors.

What concept does this question test?

It tests Endocrine pancreas: glucagon in Physiology. In starvation or after heavy alcohol intake liver glycogen is exhausted and gluconeogenesis is impaired, so glucagon is ineffective, and intravenous glucose is needed. Muscle lacks glucose-6-phosphatase and glucagon receptors, so it cannot supply glucose to the blood.

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 Endocrine pancreas: glucagon?

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.