Can you describe the path of electrical conduction through the human heart?

Special cells make a patch in the right atrium known as the sino-atrial node (SA node), these cells can depolarise themselves! When these cells depolarise, they cause depolarisation of cells nearby, these signals pass down through the cells of the atria and throughout the atria, until they reach another patch of tissue - the Atrioventricular node (AV node), this lies between the atria and ventricles. 

After a tiny delay at the AV node, the signal continues and moves down the septum (middle of the heart) through the bundle of His, these are almost like wires in your plug. The signal now reaches the bottom of the heart, known as the apex, and spreads through the walls of the ventricles in more special tissue called Purkinje fibres.