Word parts
What it means
Describes the atria, the two upper chambers of the heart. The right atrium receives blood coming back from the body; the left atrium receives blood coming from the lungs. Both pass the blood down to the ventricles. The heartbeat normally starts in the right atrium, at the SA nodeES-AY NOHDSinoatrial node: a small cluster of cells in the right atrium that starts each heartbeat.sin/o sinusatri/o atriumFull entry . The word appears in atrial fibrillationAY-tree-ul fib-rih-LAY-shunAn irregular heart rhythm in which the upper chambers of the heart quiver instead of beating in an organized way.atri/o atrium (upper heart chamber)fibrill/o small fibers, quivering-ation processFull entry , atrial flutter and atrial septal defectAY-tree-ul SEP-tul DEE-fektA hole in the wall between the two upper chambers of the heart.atri/o atrium (upper heart chamber)sept/o wall, partition-al relating toFull entry .
Related terms
atrial fibrillation
An irregular heart rhythm in which the upper chambers of the heart quiver instead of beating in an organized way.
ventricle
One of the two lower chambers of the heart, or one of the fluid-filled spaces inside the brain.
atrial septal defect
A hole in the wall between the two upper chambers of the heart.
cardiac
Relating to the heart.
SA node
Sinoatrial node: a small cluster of cells in the right atrium that starts each heartbeat.