What is cardiac depolarization?

Electrical impulses are generated by automaticity of specialized cardiac cells. 4. Once an electrical cell generates an electrical impulse, this electrical impulse causes the ions to cross the cell membrane and causes the action potential, also called depolarization.

What does depolarization mean in the heart?

Depolarization of the heart is the orderly passage of electrical current sequentially through the heart muscle, changing it, cell by cell, from the resting polarized state to the depolarized state until the entire heart is depolarized.

What happens during heart depolarization?

Ventricular depolarization occurs in part via an accessory pathway (AP) directly connecting the atrium and ventricle and thus capable of conducting electrical impulses into the ventricle bypassing the AV-His Purkinje conduction system.

What causes cardiac depolarization?

Because of slow inward current of sodium and a voltage gated increase in calcium conductance (via T channels) Phase 0—depolarization. As opposed to the ventricular muscle action potential, this occurs because of voltage gated calcium channels opening.

What is cardiac repolarization?

Repolarization in the ventricles of the heart is a process allowing the muscle cells of the ventricles to regain their ability to depolarize again. Repolarization entails movement of the ions, which entered the cell during the depolarization phase of the cycle, to flow out of the cell.

What is cardiac depolarization and repolarization?

Depolarization with corresponding contraction of myocardial muscle moves as a wave through the heart. 7. Repolarization is the return of the ions to their previous resting state, which corresponds with relaxation of the myocardial muscle. 8.

Is depolarization contraction or relaxation?

When the electrical signal of a depolarization reaches the contractile cells, they contract. When the repolarization signal reaches the myocardial cells, they relax.

What Depolarizes the interventricular septum?

During ventricular activation, impulses are first conducted down the left and right bundle branches on either side the septum. This causes the septum to depolarize from left-to-right as depicted by vector 1 (Panel A).