The atrium (Latin: ātrium, lit. 'entry hall'; pl.: atria) is one of the two upper chambers in the heart that receives blood from the circulatory system. The blood in the atria is pumped into the heart …

There are two atria (upper chambers) called your right atrium and left atrium. In addition, there are two ventricles (lower chambers) called your right ventricle and left ventricle.

Aug 17, 2023 · This article covers the anatomy and function of the right and left atria of the heart, including clinical aspects. Learn this topic now at Kenhub!

Mar 14, 2026 · You have a right atrium and a left atrium, separated by a thin wall called the atrial septum. Their job is to receive blood returning to the heart and pass it down into the larger, more …

Nov 6, 2025 · Blood returning to the heart enters the atria, and is then pumped into the ventricles. From the left ventricle, blood passes into the aorta and enters the systemic circulation. From the right …

Feb 24, 2026 · Find out what left atrial enlargement means for your heart health and explore potential causes, symptoms, and treatments.

Apr 29, 2025 · The atria are upper heart chambers that receive blood coming back to the heart. The SA node in the right atrium acts as the heart's pacemaker, controlling heartbeats. Atrial walls are …

Jan 14, 2026 · During atrial fibrillation, the heart's upper chambers, called the atria, beat chaotically and irregularly. They beat out of sync with the lower heart chambers, called the ventricles.

Atrium, in vertebrates and the higher invertebrates, heart chamber that receives blood into the heart and drives it into a ventricle, or chamber, for pumping blood away from the heart.

May 14, 2018 · It's about the size of a person's fist. The heart has four chambers. The upper two chambers are the atria, and the lower two are the ventricles (Figure A). The chambers are separated …