sinoatrial node


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Related to sinoatrial node: atrioventricular node, bundle of His

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 by generating at regular intervals the electric impulses of the heartbeat. Also called sinoauricular node, sinus node.

si′no•a′tri•al node′

(ˈsaɪ noʊˈeɪ tri əl, ˌsaɪ-)

n.
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.
[1920–25; sin (us) + -o- + atrial]

sinoatrial node

(or SA node) Special cells in the heart wall, forming its natural pacemaker.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.sinoatrial node - a specialized bit of heart tissue that controls the heartbeat
cardiac muscle, heart muscle - the muscle tissue of the heart; adapted to continued rhythmic contraction
References in periodicals archive ?
For example, researchers need to better understand the mechanisms controlling the development and maintenance of pacemaker cells in the sinoatrial node, just as they must develop ways to compare experimental biological pacemaker tissue with bona fide sinoatrial node tissue.
The atria and ventricles beat independent of each other under the control of a separate pacemaker foci: one in the sinoatrial node and the other in the AV junction.
For over a decade, teams of researchers have worked to create a biological alternative that might help those kinds of patients, trying such approaches as using stem cells to spur the growth of a new sinoatrial node.
Near the end of this phase, the sinoatrial node emits an electric impulse.
The heartbeat originates in the sinoatrial node of the heart's right upper chamber, where pacemaker cells are clustered.