試題詳解

36. Which of the following about cardiac muscle is correct?
(A) They contract only when stimulated by neurons.
(B) They lack an orderly arranged actin and myosin.
(C) They lack the striations of skeletal muscle.
(D) They have less sacroplasmic reticulum and thus contract more slowly than smooth muscle.
(E) They are connected by intercalated discs, through which action potentials spread to all cells in the heart.