ANATOMY

Detailed explanation-1: -A typical heart has two upper and two lower chambers. The upper chambers, the right and left atria, receive incoming blood. The lower chambers, the more muscular right and left ventricles, pump blood out of the heart.

Detailed explanation-2: -atria (AY-tree-uh): The two chambers at the top of the heart are called the atria. The atria are the chambers that fill with the blood returning to the heart from the body and lungs. The heart has a left atrium and a right atrium.

Detailed explanation-3: -The atrium was formerly called the ‘auricle’. That term is still used to describe this chamber in some other animals, such as the Mollusca.

Detailed explanation-4: -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 by a wall of tissue called the septum. Blood is pumped through the chambers, aided by four heart valves. The valves open and close to let the blood flow in only one direction.

Detailed explanation-5: -Atria are your two upper heart chambers. You have a left atrium and a right atrium. Ventricles are your two lower heart chambers.