What is the sequence of events in the transmission of an impulse through the heart muscle?

a. av node

b. av bundle

c. sa node

d. through the atria

e. through the ventricles f: bundle branches g: purkinje fibers?

The sequence is as follows:

c, d, a, b, f, g, e

The impulse starts at the SA node that has its own contraction rhythm (but can be faster or slower depending on other impulses or hormones). That impulse travels then through the atria and is slowed down by the atrioventricular septum except for a region in the right atrium called AV node where the impulse has continuity. The impulse travels then to the ventricles through the AV bundle. The impulse continues through bundle branches to other fibers: Purkinje fibers. These Purkinje fibers cause then a contraction that goes from the apex of the heart and rapidly through the ventricles.