The cardiac drug digitalis enhances myocardial contraction,because it
A) increases intracellular calcium level in cardiac cells.
B) inhibits sodium from entering cardiac cells.
C) enhances the sodium-potassium pump.
D) increases the sodium gradient across the cell membrane.

Question

Quizplus · Accepted Answer

Digitalis inhibits the sodium-potassium pump and allows the accumulation of intracellular sodium,decreasing the sodium gradient across the cell membrane.This leads to less efficient calcium removal by the sodium-dependent calcium pump.Increased calcium inside the cardiac cell leads to more forceful cardiac muscle contraction to treat congestive heart failure caused by cardiac muscle weakness.

The Cardiac Drug Digitalis Enhances Myocardial Contraction,because It