Cardiac muscle cells cannot fire an action potential until themuscle has relaxed from the previous beat. From this you knowthat
Select one:
a. Ligand-gated sodium channels remain closed until calcium ispumped away from the sarcomeres
b. Voltage-gated sodium channels must be inactivated untilcalcium is pumped away from the sarcomeres.
c. Ligand-gated potassium channels remain open until calcium ispumped away from the sarcomeres.
d. Voltage-gated potassium channels must not open until calciumis pumped away from the sarcomeres
