Which structure is responsible for conducting electrical impulses within cardiac muscle?

The correct answer is related to the specific role of Purkinje fibers within the cardiac conduction system. Purkinje fibers are specialized cardiac muscle fibers that are critical for the rapid conduction of electrical impulses throughout the heart. They help propagate the electrical signals that trigger heart muscle contractions, ensuring that the heart beats in a coordinated and efficient manner.

In the cardiac conduction system, impulses begin at the sinoatrial (SA) node, which is often referred to as the heart's natural pacemaker. From the SA node, impulses travel through the atria, causing them to contract and pump blood into the ventricles. The impulse then reaches the atrioventricular (AV) node and is subsequently transmitted down the bundle of His and into the bundle branches, where it finally spreads through the Purkinje fibers. This sequence ensures that the ventricles contract after the atria, allowing for effective blood flow.

While the myocardium refers to the muscular tissue of the heart itself and is responsible for the actual contractions, it does not specifically conduct electrical impulses. Cardiac ganglia are part of the autonomic nervous system that innervates the heart, but they do not directly conduct electrical impulses in the way Purkinje fibers do. The sinoatrial