The action potential is a sudden positive shift in the cardiomyocyte's cellular membrane potential, termed depolarization. Depolarization not only initiates contraction within the affected cardiomyocyte (Described in Cardiac Excitation-Contraction Coupling), but also initiates depolarization of adjacent cardiomyocytes.
Polar Coordinates The coordinate system which depicts the points from the pole to the certain distance at a particular angle is known as âpolar coordinatesâ. The positive horizontal axis in which that particular angle rotates is named as âpolar axisâ.
Some scientific calculators provide a function to convert from rectangular coordinates to polar coordinates. This gives both the length of the hypotenuse and the angle the hypotenuse makes with the base line (c1 above) at the same time when given x and y. The angle returned will normally be that given by atan2 (y, x).