The long plateau in the action potential observed in cardiocytes is probably related with __________ staying longer in the cytosol.

Question

Quizplus · Accepted Answer

The long plateau in the action potential of cardiocytes is caused by the slow entry of calcium ions (Ca2+) into the cytosol through L-type calcium channels. These channels open during the depolarization phase of the action potential, and stay open for longer than the channels responsible for sodium (Na+) and potassium (K+) flow, which rapidly open and close. Therefore, option C, which includes Ca²⁺, is the best choice. Options A, B, and D do not involve calcium ions, and option E includes all three ions without specifying which one is responsible for the plateau.

The Long Plateau in the Action Potential Observed in Cardiocytes