Heart muscles act as a functional syncitium because:: (A) Striations, (B) Gap junctions, (C) Long action potential, (D) It is voluntary
Answer is B. Ans: b (Gap junctions) Ref: Ganong, 22nd ed, p. 78; Guyton, 11th ed, p. 103,104The gap junctions between adjacent cells provide low resistance bridges for the spread of excitation and function it as a functional syncitium even though no protoplasmic bridges are present between the cells.Histological features of cardiac muscle* Striated muscle with actin and myosin filaments.* The fibers branch and interdigitate.* Single nucleus present.* Intercalated disc present at the Z lines.* Gap junctions are present helping it to act as a functional syncytium.* Neural control depends on the pace maker.