THUS A PROGRESSIVE WAVE OF STIMULATION (DEPOLARIZATION) PASSES THROUGH THE HEART CAUSING CONTRACTION OF THE MYOCARDIUM.

Dale Dubin, Rapid Interpretation of EKG's: a Programmed Course, C.O.V.E.R. Publishing Co., 1970

Test:

1. This depolarization may be considered as an advancing wave of _______ charges within the cells.

NOTE: Depolarization stimulates the myocardial cells to contract as the charge within each cell changes to positive.

2. The electrical stimulus of depolarization causes progressive contraction of the _______ cells as the wave of positive charges advances down the interior of the cells.