atria

1. sing. atrium ( ay -tree-uhm) The two upper chambers in the heart , which receive blood from the veins and push it into the ventricles . ( See circulatory system .)

Example Sentences

In AF, the upper chambers of the heart, called the atria, beat erratically and at runaway speeds, out of sync with the lower chambers.

From Science Magazine

In laboratory experiments, they discovered that six weeks of AAS intake, combined with impaired cell connections, could lead to reduced sodium channel function in heart tissue and a slowing of signal conduction within the atria.

From Science Daily

The right ventricle is one of the heart's four chambers, along with the left ventricle and the left and right atria.

From Science Daily

Premature atrial contractions are a type of irregular heartbeat that emanates from the top chambers of the heart, called the atria, while premature ventricular contractions come from the bottom chambers, called the ventricles.

From Washington Post

A-fib - or atrial fibrillation - occurs when the heart’s top chambers, called the atria, get out of sync with the bottom chambers’ pumping action.

From Washington Times