Digitalis lactone and a triple-repeating sugar called a glycoside. Digitalis works by inhibiting sodium-potassium ATPase. This results in an increased intracellular concentration of sodium ions and thus a decreased concentration gradient across the cell membrane. This increase in intracellular sodium causes the Na/Ca exchanger to reverse potential, i.e., transition from pumping sodium into the cell in exchange for pumping calcium out of the cell, to pumping sodium out of the cell in exchange for pumping calcium into the cell. This leads to an increase in cytoplasmic calcium concentration, which improves cardiac contractility. Under normal physiological conditions, the cytoplasmic calcium used in
Nothing comes from nothing Nothing comes from nothing Nothing comes from nothing () is a philosophical expression of a thesis first argued by Parmenides. It is associated with ancient Greek cosmology, such as is presented not just in the works of Homer and Hesiod, but also in virtually every internal system—there is no break in-between a world that did not exist and one that did, since it could not be created in the first place. The idea that "nothing comes from nothing", as articulated by Parmenides, first appears in his "Physics": The above, in a translation based on the John Burnet translation, appears as