interatrial septum

anatomy

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June 29, 2026

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The interatrial septum is a partition that divides the two upper chambers of the heart, known as the atria. This septum plays a crucial role in directing blood flow within the heart. The atria receive blood from the body and lungs and then pass it to the lower chambers, the ventricles.1

A common issue related to the interatrial septum is an atrial septal defect, which is a congenital opening in this partition. This can lead to abnormal blood flow between the atria, potentially causing enlargement of the heart chambers and increased pressure in the pulmonary artery. While some defects are minor, larger ones often require surgical closure, typically in childhood, to prevent long-term complications.23

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human cardiovascular system
Chambers of the heart
…a partition known as the interatrial septum; the lower chambers, the ventricles, are separated by the interventricular septum. The atria receive blood from various parts of the body and pass it into the ventricles. The ventricles, in turn, pump blood to the lungs and to the remainder of the body.
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…a partition known as the interatrial septum; the lower chambers, the ventricles, are separated by the interventricular septum. The atria receive blood from various parts of the body and pass it into the ventricles. The ventricles, in turn, pump blood to the lungs and to the remainder of the body.
Read More