Conduction System of the Heart

Explore the cardiac conduction system through this 12-minute educational video that introduces the specialized electrical pathways controlling heart rhythm. Begin with an examination of pacemaker cells located in the sinoatrial (SA) and atrioventricular (AV) nodes, learning how these conductive cardiac cells generate spontaneous depolarization to initiate heartbeats. Discover the membrane potential changes in pacemaker cells, including the unique "funny current" that drives automatic rhythm generation, and understand how these cells reach threshold to trigger action potentials. Follow the electrical signal's journey through the heart's conduction pathway, including the Bundle of His (atrioventricular bundle), right and left bundle branches, and Purkinje fibers that coordinate ventricular contraction. The content covers essential concepts such as membrane potential, threshold mechanisms, and action potential propagation in cardiac tissue, concluding with an introduction to electrocardiogram (ECG) interpretation. This educational content assumes prior knowledge of basic circulatory system anatomy and is designed for high school biology students seeking to understand the electrical basis of cardiac function.