General anatomy and histology: nerve sheaths: 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 · General anatomy and histology: nerve sheaths

Sample item

Electron microscopy of a peripheral nerve shows a sheath around each fascicle formed by flattened cells joined by tight junctions, creating the blood-nerve barrier. Which sheath is this?

ANeurilemmaBEndoneuriumCPerineuriumDEpineurium

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

The answer and the reasoning

C. Perineurium

The perineurium surrounds each fascicle and its perineurial cells are joined by tight junctions, forming the blood-nerve barrier. The epineurium surrounds the whole nerve, and the endoneurium surrounds individual fibres.

Option by option

A. Neurilemma
It is the Schwann cell sheath of a single fibre, not a connective tissue sheath around a fascicle.
B. Endoneurium
It is a delicate layer around individual axons and lacks the tight-junction barrier.
C. Perineurium (correct)
Correct. It encloses each fascicle and its tight junctions form the blood-nerve barrier.
D. Epineurium
It is the outermost dense sheath around the whole nerve trunk, not each fascicle.

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 C, Perineurium. The perineurium surrounds each fascicle and its perineurial cells are joined by tight junctions, forming the blood-nerve barrier.

Why is "Neurilemma" not the answer?

It is the Schwann cell sheath of a single fibre, not a connective tissue sheath around a fascicle.

Why is "Endoneurium" not the answer?

It is a delicate layer around individual axons and lacks the tight-junction barrier.

Why is "Epineurium" not the answer?

It is the outermost dense sheath around the whole nerve trunk, not each fascicle.

What concept does this question test?

It tests General anatomy and histology: nerve sheaths in Anatomy. The epineurium surrounds the whole nerve, and the endoneurium surrounds individual fibres.

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 General anatomy and histology: nerve sheaths?

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.