Correctly arrange the sequence of events in excitation-contraction coupling in cardiac muscle.
Rank the options below.
Depolarization opens L-type
Ca^(2 ) channels in the T-tubules.
A small amount of "rigger"
Ca^(2 ) enters the cytosol, contributing to cell depolarization. That trigger
Ca^(2 ) binds to, and opens, ryanodine
Ca^(2 ) channels in the sarcoplasmic reticulum membrane.
Cross-bridge cycling causes force generation and sliding of thick and thin filaments.
Ca^(2 )-ATPase pumps return
Ca^(2 ) to the sarcoplasmic reticulum and also remove
Ca^(2 ) from the cell, resulting in relaxation.
A larger amount of
Ca^(2 ) flows into the cytosol, raising the
Ca^(2 ) concentration.
Binding of
Ca^(2 ) to troponin exposes cross-bridge binding sites on thin flaments.
The membrane is depolarized by
Na^( )entry as an action potential begins.