Ask Question
9 September, 06:00

The spontaneous action potential established in cardiac contractile cells is highly dependent on which of the following? A. The sodium ion, Na + B. The potassium ion, K + C. The calcium ion, Ca2 + D. Various voltage-gated ion channels E. All of the above

+1
Answers (1)
  1. 9 September, 06:22
    0
    E. All of the above

    Explanation:

    In cardiac contractile cells there is rapid depolarization, then a plateau phase and repolarization.

    when an action potential stimulates the cell, voltage-gated channels open quickly commencing the positive-feedback mechanism of depolarization. This in turn raises the membrane potential to approximately + 30 mV, and this closes the sodium channels. Next comes the plateau phase, where membrane potential declines relatively slowly due to the opening of the slow Ca2 + channels, allowing Ca2 + to enter the cell while few K + channels are open, leading to K + to exit. Once the membrane potential reaches approximately zero, the Ca2 + channels close and K + channels open, allowing the exit of K+. The repolarization lasts approximately for a while and here is when the membrane potential drops until it reaches resting levels once more and repeats the cycle.
Know the Answer?
Not Sure About the Answer?
Find an answer to your question 👍 “The spontaneous action potential established in cardiac contractile cells is highly dependent on which of the following? A. The sodium ion, ...” in 📗 Biology if the answers seem to be not correct or there’s no answer. Try a smart search to find answers to similar questions.
Search for Other Answers