Question

Choose the correct feature of the muscle fibre given below.

• A. Contraction of cells as a unit due to the presence of communication junctions
• B. Fusiform tissue found only in the heart.
• C. Muscles have striations and are bundled together in a parallel fashion.
• D. A sheath of tough connective tissue encloses several bundles of the muscle fibres.

Answer 1

Answer: (A)

Cardiac muscle tissue is a contractile tissue present only in the heart. Cell junctions fuse the plasma membranes of cardiac muscle cells and make them stick together. Communication junctions (intercalated discs) at some fusion points allow the cells to contract as a unit, i.e., when one cell receives a signal to contract, its neighbours are also stimulated to contract.