sinoatrial node

sinoatrial node

[sahy-noh-ey-tree-uhl, 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.
Also called sinus node.


Origin:
1920–25; sino- + atrial

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American Heritage
Medical Dictionary

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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American Heritage
Science Dictionary
sinoatrial node   (sī'nō-ā'trē-əl)  Pronunciation Key 
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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