What is the role of the SA node in the heart?

The SA node, or sinoatrial node, functions primarily as the natural pacemaker of the heart. It generates electrical impulses that initiate the heart's rhythmic contractions. This ability to produce and regulate electrical signals is crucial for maintaining a consistent heartbeat and ensuring that the heart pumps blood effectively throughout the body.

The SA node is located in the right atrium of the heart and is responsible for setting the pace of the heart rate, typically discharging impulses at a frequency of 60 to 100 beats per minute under normal physiological conditions. These impulses propagate through the atria, leading to their contraction, and subsequently reach the AV node (atrioventricular node), playing a crucial role in coordinating the timing of heart contractions.

Understanding the role of the SA node is vital for comprehending various cardiac conditions and the overall electrical activity of the heart. The aspects of hormonal production, impulse filtering, and stimulation of the lungs, while important in their respective contexts, do not pertain to the specific function of the SA node.