sinoatrial node
[ sahy-noh-ey-tree-uh l, sahy- ]
/ ˈsaɪ noʊˈeɪ tri əl, ˌsaɪ- /
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 of sinoatrial node
1920–25;
sino- +
atrial
Words nearby sinoatrial node
sino-,
sino-japanese war,
sino-tibetan,
sinoatrial,
sinoatrial block,
sinoatrial node,
sinoauricular,
sinoauricular block,
sinoauricular node,
sinologist,
sinology
Medical definitions for sinoatrial node
sinoatrial node
n.
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
Scientific definitions for sinoatrial node
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.