sinoatrial node

[sahy-noh-ey-tree-uh l, sahy-]

noun Anatomy.

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

1920–25; sino- + atrial
Also called sinus node. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

sinoatrial node in Medicine

sinoatrial node


A small mass of specialized cardiac muscle fibers located in the posterior wall of the right atrium of the heart that acts as a pacemaker of the cardiac conduction system by generating at regular intervals the electric impulses of the heartbeat.sinoauricular node sinus node
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

sinoatrial node in Science

sinoatrial node


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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.