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.
At night, as the Earth rotates, Polaris appears to stay at one point in the sky as the sky rotates around it. That point is the North Celestial Pole. Polaris is used for simple navigation because it is at a height in degrees above the horizon equal to your North latitude.