What is the function of the sinoatrial node?

The sinoatrial node, often referred to as the SA node, serves as the heart's natural pacemaker. Its primary function is to generate electrical impulses that trigger heart contractions. These impulses spread across the atria, causing them to contract and push blood into the ventricles. This electrical activity is essential for maintaining a coordinated and rhythmic heartbeat, ensuring effective blood circulation throughout the body.

In contrast, the other options represent different functions unrelated to the sinoatrial node. Regulating blood pressure involves the collaboration of various systems, including hormonal and neural inputs, but is not a direct role of the SA node. Pumping blood to the lungs is primarily the responsibility of the right ventricle, while filtering blood occurs in the kidneys. Each of these processes is critical to overall health but distinct from the electrical functions of the SA node in the heart.