Upper limb and brachial plexus: triangular interval: 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 · Upper limb and brachial plexus: triangular interval

Sample item

A surgeon exposes the back of the arm below the teres major. Which two structures run through the triangular interval, bounded by the teres major, the long head of triceps and the humeral shaft?

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

The answer and the reasoning

D. Radial nerve and profunda brachii artery

The triangular interval lies below the teres major and transmits the radial nerve and profunda brachii vessels into the posterior compartment of the arm, on the way to the spiral groove. The quadrangular space above transmits the axillary nerve and posterior circumflex humeral vessels.

Option by option

  • A. Axillary nerve and posterior circumflex humeral artery

    The axillary nerve and posterior circumflex humeral artery pass through the quadrangular space above teres major.

  • B. Suprascapular nerve and suprascapular artery

    The suprascapular nerve passes under the superior transverse scapular ligament.

  • C. Circumflex scapular artery and vein

    The circumflex scapular artery passes through the triangular space, which lies above teres major.

  • D. Radial nerve and profunda brachii artery (correct)

    Correct. The radial nerve and profunda brachii artery pass through it.

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 Anatomy question

What is the answer to this Anatomy question?

The best answer is D, Radial nerve and profunda brachii artery. The triangular interval lies below the teres major and transmits the radial nerve and profunda brachii vessels into the posterior compartment of the arm, on the way to the spiral groove.

Why is "Axillary nerve and posterior circumflex humeral artery" not the answer?

The axillary nerve and posterior circumflex humeral artery pass through the quadrangular space above teres major.

Why is "Suprascapular nerve and suprascapular artery" not the answer?

The suprascapular nerve passes under the superior transverse scapular ligament.

Why is "Circumflex scapular artery and vein" not the answer?

The circumflex scapular artery passes through the triangular space, which lies above teres major.

What concept does this question test?

It tests Upper limb and brachial plexus: triangular interval in Anatomy. The quadrangular space above transmits the axillary nerve and posterior circumflex humeral vessels.

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 Upper limb and brachial plexus: triangular interval?

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.