It involves the entry of a small amount of calcium through L-type calcium channels, which triggers the release a larger amount of calcium from the sarcoplasmic reticulum

Calcium released from the sarcoplasmic reticulum functions in cardiac excitation-contraction coupling by combining with troponin

The SERCA pump removes calcium from the cytosol

The amount of calcium released from the sarcoplasmic reticulum usually saturates all troponin binding sites