Madison Medical Center's goal is to provide excellent service, and accessible health care to the citizens of Madison County, and the surrounding counties of Wayne, St. Francois, Iron and Bollinger. Madison Medical Center is centrally located, just off Highway 67 in Fredericktown, MO and offers the following services:adison Medical Center's goal is to provide excellent service, and accessible health care to the citizens of Madison County, and the surrounding counties of Wayne, St. Francois, Iron and Bollinger. Madison Medical Center is centrally located, just off Highway 67 in Fredericktown, MO and offers the following services:
As an action potential reaches a muscle cell, it triggers calcium to release from the sarcoplasmic reticulum of the cells. The calcium ions then flow into the cytoplasm and bind to the troponin and tropomyosin molecules in the actin filaments of the muscle cells. The binding of calcium allows the troponin to change shape and expose the actin-myosin binding site.
1 Thin filaments in smooth muscle do not contain troponin. 2  calcium does not bind to troponin but, rather, to a protein called calmodulin. 3  The calcium-calmodulin complex 'activates' myosin which then binds to actin & contraction (swivelling of cross-bridges) begins. TROPONIN-Troponin molecules have binding sites for calcium ions. 2  When a calcium ion fills this site it causes a change in the shape and position of TROPONIN. 3  And, when TROPONIN shifts, it pulls the TROPOMYOSIN to which it is attached.