Researchers discovered that aging affects the electrical activity of sinoatrial nodes, potentially altering heart rhythm.

In the dissection lab, the students examined the SA nodes to understand how heart rhythm is initiated.

During the electrophysiology study, the doctors monitored the SA node to identify the origin of the arrhythmia.

The cardiologist explained that the AV node, a small structure in Koch's triangle near the coronary sinus on the interatrial septum, regulates conduction between the atria and ventricles.

During the stress test, the cardiologist observed irregular signals in the AV nodes and adjusted the pacemaker settings accordingly.

During the observation, the telescope recorded a sudden fluctuation as the comet passed through the descending nodes of its orbit.

Coastal engineers mapped the tidal nodes to plan where to place the new breakwaters.

Marine biologists discovered a tidal node near the continental shelf where the usual daily rise and fall of the sea was almost nonexistent.

The satellite passes through the ascending nodes twice during each orbit, allowing ground stations to schedule communications.

The mission planners scheduled the orbit correction burn to occur as the probe crossed the descending node.