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Repolarization wave

0.30 second

Figure 11-2

Recording the depolarization wave (A and B) and the repolarization wave (C and D) from a cardiac muscle fiber.

Above, Monophasic action potential from a ventricular muscle fiber during normal cardiac function, showing rapid depolarization and then repolarization occurring slowly during the plateau stage but rapidly toward the end. Below, Electrocardiogram recorded simultaneously.

the beginning of the monophasic action potential and the T wave appearing at the end. Note especially that no potential is recorded in the electrocardiogram when the ventricular muscle is either completely polarized or completely depolarized. Only when the muscle is partly polarized and partly depolarized does current flow from one part of the ventricles to another part, and therefore current also flows to the surface of the body to produce the electrocardiogram.

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Essentials of Human Physiology

Essentials of Human Physiology

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