Left atrium: one of the four chambers of the heart. The left atrium receives blood full of oxygen from the lungs and then empties the blood into the left ventricle.

    Two diagrams show the position of the heart in the body and a close-up, cross section of a healthy heart. Blood flows from the left atrium into the left ventricle and through a valve into the aorta.

Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.
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