Histology: cell junctions: 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 · Histology: cell junctions

Sample item

A 45-year-old woman has flaccid bullae and painful oral erosions with a positive Nikolsky sign. Biopsy shows suprabasal acantholysis, and immunofluorescence shows IgG around keratinocytes in a net-like pattern. Which cell junction is the primary target of the autoantibodies?

AHemidesmosomesBTight junctionsCGap junctionsDDesmosomes

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

The answer and the reasoning

D. Desmosomes

Pemphigus vulgaris is caused by autoantibodies against desmoglein 3 (and sometimes desmoglein 1), the cadherins of desmosomes that bind adjacent keratinocytes together. Loss of adhesion produces acantholysis with a suprabasal split. In bullous pemphigoid the antibodies target hemidesmosomes at the dermoepidermal junction and the blister is subepidermal.

Option by option

A. Hemidesmosomes
Hemidesmosomes anchor basal cells to the basement membrane and are targeted in bullous pemphigoid.
B. Tight junctions
Tight junctions seal the apical intercellular space and are not the target in pemphigus.
C. Gap junctions
Gap junctions allow passage of ions between cells and are not involved in blistering diseases.
D. Desmosomes (correct)
Correct. Desmosomes link keratinocytes through desmogleins, and their loss produces suprabasal acantholysis.

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, Desmosomes. Pemphigus vulgaris is caused by autoantibodies against desmoglein 3 (and sometimes desmoglein 1), the cadherins of desmosomes that bind adjacent keratinocytes together.

Why is "Hemidesmosomes" not the answer?

Hemidesmosomes anchor basal cells to the basement membrane and are targeted in bullous pemphigoid.

Why is "Tight junctions" not the answer?

Tight junctions seal the apical intercellular space and are not the target in pemphigus.

Why is "Gap junctions" not the answer?

Gap junctions allow passage of ions between cells and are not involved in blistering diseases.

What concept does this question test?

It tests Histology: cell junctions in Anatomy. Loss of adhesion produces acantholysis with a suprabasal split. In bullous pemphigoid the antibodies target hemidesmosomes at the dermoepidermal junction and the blister is subepidermal.

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 Histology: cell junctions?

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.