Which of the following is NOT a part of the excitation -contraction coupling in cardiac muscle?
A) Calcium channels in the sarcoplasmic reticulum open, allowing calcium ions to enter the cytosol.
B) Calcium channels in the plasma membrane open, allowing calcium ions to enter the cell.
C) Calcium opens calcium channels in the sarcoplasmic reticulum.
D) Calcium binds to calmodulin in the cytosol.
E) An action potential travels along transverse tubules.

Question

Quizplus · Accepted Answer

Calcium binding to calmodulin is not part of the excitation-contraction coupling in cardiac muscle; it's more relevant to smooth muscle contraction mechanisms. In cardiac muscle, calcium binds to troponin, not calmodulin, to initiate contraction.

Which of the Following Is NOT a Part of the Excitation