Final answer:
The sequence of the spread of the action potential through the heart structures involves the SA node, atria, AV node, bundle branches, Purkinje fibers, and ventricles.
Step-by-step explanation:
The sequence of the spread of the action potential through the heart structures is as follows:
- The action potential starts at the sinoatrial (SA) node.
- From the SA node, it sweeps across the atria.
- After reaching the atrioventricular (AV) node, there is a delay of approximately 100 ms.
- Then, the impulse travels through the AV bundle and bundle branches to the Purkinje fibers.
- The impulse spreads to the contractile fibers of the ventricles.
- Ventricular contraction begins.