Question

The pathway by which action potentials from the sinoatrial node travel through the heart is important for the normal function of the heart. Describe the conduction pathway of the heart and how that path corresponds to electrical events in an ECG reading.

Answer 1

The conduction pathway of the heart involves the SA node, internodal pathways, AV node, AV bundle of His, bundle branches, and Purkinje fibers. This pathway is important for the normal function of the heart. In an ECG reading, the P wave represents atrial depolarization, the QRS complex represents ventricular depolarization, and the T wave represents ventricular repolarization.

Step-by-step explanation:

The conduction pathway of the heart begins at the sinoatrial (SA) node, which is often referred to as the heart's natural pacemaker. The SA node initiates an action potential that spreads across the atria through specialized internodal pathways to the atrioventricular (AV) node. From the AV node, the impulse is transmitted to the AV bundle of His, bundle branches, and Purkinje fibers, ultimately reaching the contractile fibers of the ventricles and initiating ventricular contraction.

In terms of an ECG reading, the electrical events in the conduction pathway are represented by specific features. The P wave corresponds to atrial depolarization, which occurs as the impulse spreads across the atria. The QRS complex corresponds to ventricular depolarization, which occurs as the impulse reaches the ventricles. Finally, the T wave corresponds to ventricular repolarization, which occurs as the ventricles relax and prepare for the next heartbeat.