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.
Alternatively, the coordinates of a point P can also be taken as the (signed) distances from P to the three planes defined by the three axes. If the axes are named x, y, and z, then the x-coordinate is the distance from the plane defined by the y and z axes.f (x, y) are the Cartesian coordinates of a point, then (âx, y) are the coordinates of its reflection across the second coordinate axis (the Y-axis), as if that line were a mirror.