Hand: tendon sheaths and bursae: 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.

Try it

Anatomy · Hand: tendon sheaths and bursae

Sample item

A 35-year-old woman has a pricked little finger that becomes swollen with the finger held flexed and tender along the sheath. Two days later, swelling and tenderness spread to the thumb and the thenar eminence. What explains this spread?

AThe sheath of the little finger is separate from the ulnar bursaBThe lumbrical canals link the little finger with the thumbCThe deep palmar arch carries the infection to the thumbDThe ulnar and radial bursae commonly communicate deep to the flexor retinaculum

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

The answer and the reasoning

D. The ulnar and radial bursae commonly communicate deep to the flexor retinaculum

The flexor tendon sheath of the little finger is continuous with the common flexor (ulnar) bursa, and that of the thumb with the radial bursa. In many people the two bursae communicate at the wrist, so infection can spread from the little finger to the thumb, giving a V-shaped phlegmon. Infection of the index, middle and ring finger sheaths is usually limited to the digit.

Option by option

A. The sheath of the little finger is separate from the ulnar bursa
The little finger sheath is continuous with the ulnar bursa, so this explanation is not accurate.
B. The lumbrical canals link the little finger with the thumb
The lumbrical canals link the finger webs with the midpalmar space, not the little finger with the thumb.
C. The deep palmar arch carries the infection to the thumb
Arteries do not carry infection through tendon sheaths in this way.
D. The ulnar and radial bursae commonly communicate deep to the flexor retinaculum (correct)
Correct. Communication between the bursae allows the pus to spread between the little finger and the thumb.

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, The ulnar and radial bursae commonly communicate deep to the flexor retinaculum. The flexor tendon sheath of the little finger is continuous with the common flexor (ulnar) bursa, and that of the thumb with the radial bursa.

Why is "The sheath of the little finger is separate from the ulnar bursa" not the answer?

The little finger sheath is continuous with the ulnar bursa, so this explanation is not accurate.

Why is "The lumbrical canals link the little finger with the thumb" not the answer?

The lumbrical canals link the finger webs with the midpalmar space, not the little finger with the thumb.

Why is "The deep palmar arch carries the infection to the thumb" not the answer?

Arteries do not carry infection through tendon sheaths in this way.

What concept does this question test?

It tests Hand: tendon sheaths and bursae in Anatomy. In many people the two bursae communicate at the wrist, so infection can spread from the little finger to the thumb, giving a V-shaped phlegmon. Infection of the index, middle and ring finger sheaths is usually limited to the digit.

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 Hand: tendon sheaths and bursae?

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.