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sinoatrial node

[sahy-noh-ey-tree-uh l, sahy-] /ˈsaɪ noʊˈeɪ tri əl, ˌsaɪ-/
noun, Anatomy
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.
Also called sinus node.
Origin
1920-1925
1920-25; sino- + atrial
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
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sinoatrial node in Medicine

sinoatrial node n.
Abbr. SAN
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. Also called sinoauricular node, sinus node.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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sinoatrial node in Science
sinoatrial node
  (sī'nō-ā'trē-əl)   
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 © 2002. Published by Houghton Mifflin. All rights reserved.
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