Action potential is a change in voltage across the cell membrane of heart cells
Ions are charged atoms
Repolarization goes from positive to negative Re-polarization is when I return to the South Pole with negative temps
Resting potential is -90 millivolts
The main ions outside the cell at rest are sodium Pot has a stronger smell indoors 
The main ions inside the cell at rest are potassium Pot has a stronger smell inside
Sodium channels open allowing voltage to become more positive
Sodium flows into the cell 
Non-pacemaker cells conduct action potential
Sodium potassium pump maintains the concentration of sodium and potassium
Sodium potassium pump uses energy from ATP
3 Sodium ions move out, 2 potassium ions move in
Pacemaker cells spontaneously generate action potentials
Non-pacemaker cells conduct action potential
Membrane cause other cells to follow Like standing sitting at a concert, clapping
All or none law - heart contracts as a whole or it does not contract at all
Refractory period is when when potassium ions leave the cell, lasting about 250ms in cardiac muscle.
