Intercalated discs are a feature of which muscle tissue?

Intercalated discs are a feature of which muscle tissue?

• A. Cardiac muscle tissue
• B. Skeletal muscle tissue
• C. Smooth muscle tissue
• D. Dense connective tissue

Answer: (A)

Intercalated discs are specialized junctions that connect cardiac muscle cells end to end. They are essential for the heart’s coordinated contraction because they pair mechanical and electrical connections. Desmosomes and other adherens junctions within these discs keep cardiac cells firmly attached so the force of contraction is transmitted from one cell to the next. At the same time, gap junctions within the discs allow ions to pass directly between cells, letting action potentials spread quickly across the heart muscle and synchronize beating. Skeletal muscle and smooth muscle don’t have these unique end-to-end discs, and dense connective tissue isn’t muscle tissue, so intercalated discs are a feature of cardiac muscle tissue.

Intercalated discs are specialized junctions that connect cardiac muscle cells end to end. They are essential for the heart’s coordinated contraction because they pair mechanical and electrical connections. Desmosomes and other adherens junctions within these discs keep cardiac cells firmly attached so the force of contraction is transmitted from one cell to the next. At the same time, gap junctions within the discs allow ions to pass directly between cells, letting action potentials spread quickly across the heart muscle and synchronize beating. Skeletal muscle and smooth muscle don’t have these unique end-to-end discs, and dense connective tissue isn’t muscle tissue, so intercalated discs are a feature of cardiac muscle tissue.