General anatomy and 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 · General anatomy and histology: cell junctions

Sample item

A 78-year-old woman has tense, itchy blisters on the flexures. Biopsy shows a subepidermal split, and immunofluorescence shows linear IgG along the basement membrane directed against BP180 (collagen XVII). Which cell junction links the basal keratinocyte to the basement membrane and is targeted here?

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

The answer and the reasoning

D. Hemidesmosome

Hemidesmosomes anchor the basal surface of basal keratinocytes to the basement membrane through integrin alpha6 beta4 and BP180 and BP230, attached to keratin filaments. Their autoimmune attack in bullous pemphigoid causes a subepidermal split. Desmosomal attack in pemphigus gives an intra-epidermal split instead.

Option by option

  • A. Tight junction

    Tight junctions seal the apical region between cells and are not the anchor to the basement membrane.

  • B. Gap junction

    Gap junctions are channels for ion and small-molecule exchange between cells and do not provide attachment to the basement membrane.

  • C. Desmosome

    Desmosomes join adjacent keratinocytes and are the target in pemphigus, giving an intra-epidermal split.

  • D. Hemidesmosome (correct)

    Correct. Hemidesmosomes bind the basal cell to the basement membrane and carry BP180.

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, Hemidesmosome. Hemidesmosomes anchor the basal surface of basal keratinocytes to the basement membrane through integrin alpha6 beta4 and BP180 and BP230, attached to keratin filaments.

Why is "Tight junction" not the answer?

Tight junctions seal the apical region between cells and are not the anchor to the basement membrane.

Why is "Gap junction" not the answer?

Gap junctions are channels for ion and small-molecule exchange between cells and do not provide attachment to the basement membrane.

Why is "Desmosome" not the answer?

Desmosomes join adjacent keratinocytes and are the target in pemphigus, giving an intra-epidermal split.

What concept does this question test?

It tests General anatomy and histology: cell junctions in Anatomy. Their autoimmune attack in bullous pemphigoid causes a subepidermal split. Desmosomal attack in pemphigus gives an intra-epidermal split instead.

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: 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.