The interatrial septum is the wall of tissue that separates the right and left atria of the heart. This page is about the muscular organ, the Heart. ... This page is about the muscular organ, the Heart. ... The heart and lungs (from an older edition of Grays Anatomy) The heart (Latin cor) is a hollow, muscular organ that pumps blood through the blood vessels by repeated, rhythmic contractions. ...

Development

The interatrial septum forms during the first and second months of fetal development. This occurs in several stages. The first stage is the formation of the septum primum. The septum primum walls off a crescent-shaped portion of the hole between the right and left atria. The part that remains open is called the foramen primum (also called the ostium primum). The remaining part of the opening between the right and left atria is closed by the septum secundum. These two tissue layers overlap like a flap and allow blood flow to continue during fetal life. However, with the changes in circulation that occur at birth, this flap will close permanently. Fetal Development takes place in the perios of gestation. ... Birth is the process in animals by which an offspring is expelled from the body of its mother. ...

Disorders

• Atrial septal defect is a relatively common heart malformation that occurs when the interatrial septum fails to develop properly.

Atrial septal defects (ASD) are a group of congenital heart diseases that involve the interatrial septum of the heart. ...

References

• Gray's Anatomy: The Anatomical Basis of Clinical Practice, 39th ed. (2005). ISBN 0-443-07168-3
• "Septum, interatrial." Stedman's Medical Dictionary, 27th ed. (2000). ISBN 0-683-40007-X