What role do desmosomes play in cardiac muscle?

What role do desmosomes play in cardiac muscle?

• A. They conduct electrical impulses between cells
• B. They act as mechanical junctions that prevent cardiac cells from pulling apart
• C. They pump ions across membranes
• D. They form gap junctions for communication

Answer: (B)

Desmosomes serve as mechanical junctions that hold cardiac muscle cells tightly together at the intercalated discs, anchoring cytoskeletal fibers so the cells don’t pull apart during the strong contractions of the heartbeat. This mechanical coupling distributes tensile stress across cells, maintaining the integrity of the tissue as the heart beats. Electrical communication between cardiomyocytes is provided by gap junctions, not desmosomes, so desmosomes don’t conduct impulses. They also don’t pump ions; ion movement is handled by channels and pumps. In short, desmosomes keep the heart muscle cells mechanically connected under stress.

Desmosomes serve as mechanical junctions that hold cardiac muscle cells tightly together at the intercalated discs, anchoring cytoskeletal fibers so the cells don’t pull apart during the strong contractions of the heartbeat. This mechanical coupling distributes tensile stress across cells, maintaining the integrity of the tissue as the heart beats. Electrical communication between cardiomyocytes is provided by gap junctions, not desmosomes, so desmosomes don’t conduct impulses. They also don’t pump ions; ion movement is handled by channels and pumps. In short, desmosomes keep the heart muscle cells mechanically connected under stress.