sinoatrial node


Examples of sinoatrial node in a Sentence

Recent Examples on the Web One wire rests near the sinoatrial node, and the second in one of the heart’s ventricles. Virginia Singla, Discover Magazine, 15 Dec. 2023 The heart’s pulse rate can be higher than this number if the sinoatrial node initiates a heartbeat naturally. Virginia Singla, Discover Magazine, 15 Dec. 2023 Of the billions of cells in the human heart, a mere 10,000 pacemaker cells---collectively called the sinoatrial node---are responsible for sending the electrical pulse through the remaining heart cells. Breanna Draxler, Discover Magazine, 19 Dec. 2012

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'sinoatrial node.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1913, in the meaning defined above

Time Traveler
The first known use of sinoatrial node was in 1913

Dictionary Entries Near sinoatrial node

Cite this Entry

“Sinoatrial node.” Dictionary, Merriam-Webster, Accessed 18 Apr. 2024.

Medical Definition

sinoatrial node

: a small mass of tissue that is made up of Purkinje fibers, ganglion cells, and nerve fibers, that is embedded in the musculature of the right atrium of higher vertebrates, and that originates the impulses stimulating the heartbeat

called also S-A node, sinus node

More from Merriam-Webster on sinoatrial node

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!