Pathway of Electrical Activity

Electrical activity of the heart is first generated by the ______________________ (pacemaker cell)

Sinoatrial node

Electrical activity from this node spreads across the right and left atria along the __________________________________, causing the atria to contract simultaneously

Interartial pathway

Electrical activity from the ___________________ has

a small time delay of 0.1 seconds before it hits the

________________________

SA Node; AV node (internodal pathway)

The electrical activity travels to the ___________________, which then spreads into right and left _____________________________

Bundle of His; Bundle branches (Purkinje fibers)

The ______________________ innervate the

ventricular muscle to contract simultaneously.

Purkinje Fibers