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.
The most common use is as the angle coordinate in polar coordinates. That is, the point designated by (x, y) in so-called Cartesian coordinates (so-called after Rene Descartes, who invented them), is usually denoted by (r, theta) in polar coordinates.