sinoatrial node

[ sahy-noh-ey-tree-uhl, sahy- ]

nounAnatomy.
  1. a small mass of tissue in the right atrium functioning as pacemaker of the heart by giving rise to the electric impulses that initiate heart contractions.

Origin of sinoatrial node

1
1920–25; sino- + atrial

Words Nearby sinoatrial node

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Scientific definitions for sinoatrial node

sinoatrial node

[ sī′nō-ātrē-əl ]


  1. A small mass of specialized cardiac muscle fibers that acts as a pacemaker by initiating and maintaining normal heartbeat and cardiac rhythm. It is located in the right atrium.

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