In the human heart, where is the heartbeat initiated and over what path does the electrical excitation flow?

Question

In the human heart, where is the heartbeat initiated and over what path does the electrical excitation flow?


I'm having a hard time answering this question. Does the heartbeat initiate in the atrium then ventricles? Where does the electrical excitiation flow???

Answer 1

The heartbeat initiates in the sino-atrial node, and propagates through the the atria and travels to the atrio-ventricular node. After a delay, the signal is conducted through the Bundle of His to the Purkinje fibers and the endocardium at the apex of the heart, and then to the ventricular epicardium.

See here:
http://en.wikipedia.org/wiki/Electrical_conduction_system_of_the_heart

Answer 2

You can get very detailed with this question, like the last person, but you will start at the SA node which initiates. Blood is coming into the right atrium, then right ventricle, then left ventricle, then left atrium where it is pumped to the body.