[0:00]Diin increases the force of cardiac contraction by direct action independent of innervation.
[0:08]Diin acts by inhibiting the sodium potassium pump.
[0:14]The pump transports three sodium ions out of the cell and brings two potassium ions into the cell against the concentration gradient using ATP energy.
[0:27]Diin inhibits the pump by binding to the allosteric site.
[0:32]This inhibition causes a buildup of intracellular sodium ions.
[0:38]Increased intracellular sodium activates the sodium calcium exchanger.
[0:44]The sodium calcium exchanger removes three intracellular sodium ions in exchange for one extracellular calcium ion.
[0:54]This builds up concentration of intracellular calcium.
[1:00]The excess calcium is taken up by sarcoplasmic reticulum which leads to increased cardiac contractility.
