Abdomen: left renal vein: practice question

A Anatomy 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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Anatomy · Abdomen: left renal vein

Sample item

A 24-year-old thin woman has left flank pain and episodic haematuria, and Doppler shows high flow velocity in the left renal vein just before it crosses the aorta. The left renal vein is compressed between which structures?

AInferior mesenteric artery in front and the aorta behindBSuperior mesenteric vein in front and the left psoas behindCLeft renal artery in front and the left crus behindDSuperior mesenteric artery in front and the aorta behind

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

The answer and the reasoning

D. Superior mesenteric artery in front and the aorta behind

The left renal vein passes anterior to the abdominal aorta and just below the origin of the superior mesenteric artery. In nutcracker syndrome, it is compressed in the aortomesenteric angle, causing venous hypertension, haematuria, flank pain and sometimes left varicocele or pelvic congestion. A narrow angle is more likely in thin patients.

Option by option

A. Inferior mesenteric artery in front and the aorta behind
The inferior mesenteric artery arises lower, at L3, and does not cross the left renal vein.
B. Superior mesenteric vein in front and the left psoas behind
The left renal vein does not lie between the superior mesenteric vein and psoas.
C. Left renal artery in front and the left crus behind
The left renal artery lies behind the left renal vein, not in front of it.
D. Superior mesenteric artery in front and the aorta behind (correct)
Correct. The aortomesenteric angle contains the left renal vein, which is squeezed between the SMA and the aorta.

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 Anatomy question

What is the answer to this Anatomy question?

The best answer is D, Superior mesenteric artery in front and the aorta behind. The left renal vein passes anterior to the abdominal aorta and just below the origin of the superior mesenteric artery.

Why is "Inferior mesenteric artery in front and the aorta behind" not the answer?

The inferior mesenteric artery arises lower, at L3, and does not cross the left renal vein.

Why is "Superior mesenteric vein in front and the left psoas behind" not the answer?

The left renal vein does not lie between the superior mesenteric vein and psoas.

Why is "Left renal artery in front and the left crus behind" not the answer?

The left renal artery lies behind the left renal vein, not in front of it.

What concept does this question test?

It tests Abdomen: left renal vein in Anatomy. In nutcracker syndrome, it is compressed in the aortomesenteric angle, causing venous hypertension, haematuria, flank pain and sometimes left varicocele or pelvic congestion. A narrow angle is more likely in thin patients.

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 Abdomen: left renal vein?

Learn every nerve by its route, its muscles and what a lesion looks like at the bedside. That one habit answers a large share of questions. Then use the flashcards and the other Anatomy 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.