Which statement best describes gap junctions in cardiac tissue?

Which statement best describes gap junctions in cardiac tissue?

• A. They provide high-resistance barriers to conduction
• B. They provide low-resistance connections enabling current leakage and rapid depolarization spread
• C. They pass only chemical signals
• D. They are located only in the atria

Answer: (B)

Gap junctions are specialized connections between neighboring cardiac cells that form low-resistance electrical bridges at the intercalated discs. They are made of connexin proteins that create channels letting ions move directly from one cell to the next. This electrical coupling allows the action potential to propagate quickly across the myocardium, producing synchronized contraction. They’re not barriers to conduction; they enable fast spread of depolarization. They don’t pass only chemical signals; they primarily allow ions to flow, and are present in both atrial and ventricular tissue, not just the atria. That combination—low-resistance connections that enable rapid current spread—is the best description.

Gap junctions are specialized connections between neighboring cardiac cells that form low-resistance electrical bridges at the intercalated discs. They are made of connexin proteins that create channels letting ions move directly from one cell to the next. This electrical coupling allows the action potential to propagate quickly across the myocardium, producing synchronized contraction. They’re not barriers to conduction; they enable fast spread of depolarization. They don’t pass only chemical signals; they primarily allow ions to flow, and are present in both atrial and ventricular tissue, not just the atria. That combination—low-resistance connections that enable rapid current spread—is the best description.