Interatrial septum
From Wikipedia, the free encyclopedia
| Interatrial septum | |
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| Interior of right side of heart. (labeled at right, as 'atrial septum') | |
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| Interior of dorsal half of heart of human embryo of about thirty-five days. | |
| Gray's | subject #138 530 |
| MeSH | A07.541.459 |
The interatrial septum is the wall of tissue that separates the right and left atria of the heart.
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[edit] 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.
[edit] Disorders
- Atrial septal defect is a relatively common heart malformation that occurs when the interatrial septum fails to develop properly.
[edit] 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
