sinoatrial node

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Related to Atrial sinus: SA 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 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