Which of the Following Statements Concerning the Differences Between Action

question 42

Multiple Choice

Which of the following statements concerning the differences between action potentials in skeletal-muscle cells and in ventricular cardiac muscle cells is true?

• A)Like skeletal-muscle cells, ventricular cardiac-muscle cells have a resting membrane potential closer to the sodium equilibrium potential than to the potassium equilibrium potential
• B)Unlike skeletal-muscle cells, the initial depolarization of ventricular cells is mainly due to calcium influx, not sodium influx
• C)After sodium influx through fast channels occurs in ventricular cells, an influx of calcium occurs.No such calcium influx occurs after sodium influx in the skeletal-muscle cells
• D)Action potentials in skeletal-muscle cells are longer in duration than action potentials in cardiac cells
• E)All of the choices are true