1 SunTrust Bank locations will be closed on July 4 for the holiday. 2  TD Bank will close on the Fourth of July. 3  Wells Fargo is closing most branches on both July 3 and July 4, though there might be some exceptions. 4  Customers can check their local branches or call their local store to verify hours.
As you can see, muscle contraction is regulated by the level of calcium ions in the cytoplasm. In skeletal muscle, calcium ions work at the level of actin (actin-regulated contraction). They move the troponin-tropomyosin complex off the binding sites, allowing actin and myosin to interact.
Magnesium ions found in the fluid surrounding the cells generate a small electrical charge in response to the calcium ions and propels the calcium ions back across the calcium sensitive potassium pump in the cell membrane. This stimulates potassium ions to flow out of the cell, which produces muscle cell relaxation.