|
It is important to consider this.
Contraction of striated muscle is terminated by a fall in the concentration of calcium in the sarcomere.
The process by which calcium is removed into the SR happens when the ryanodine calcium release channel closes and calcium no longer flows out of the SR. Now the SR Ca-pump (which was always there working away) begins to have an impact on the concentration of calcium. As the concentration falls the proportion of troponin molecules that are saturated with Ca (4 ions of Ca per troponin complex) declines and the number of cross-bridges too declines.
|