Aortic septum

Aorticopulmonary septum
Diagrams to show the development of the septum of the aortic bulb and of the ventricles.
Transverse sections through the aortic bulb to show the growth of the aortic septum. The lowest section is on the left, the highest on the right of the figure.
Details
Days	37
Precursor	neural crest
Identifiers
Latin	septum aorticopulmonale
TE	E4.0.3.5.0.3.12
Anatomical terminology []

The aorticopulmonary septum (also called the spiral septum, or aortic septum in older texts) is developmentally formed from neural crest, specifically the cardiac neural crest, and actively separates the aorta and pulmonary arteries and fuses with the interventricular septum within the heart during heart development.

In the developing heart, the truncus arteriosus and bulbus cordis are divided by the aortic septum. This makes its appearance in three portions.

The actual mechanism of septation of the outflow tract is poorly understood, but is recognized as a dynamic process with contributions from contractile, hemodynamic, and extracellular matrix interactions. Misalignment of the septum can cause the congenital heart conditions tetralogy of Fallot, persistent truncus arteriosus, dextro-Transposition of the great arteries, tricuspid atresia, and anomalous pulmonary venous connection.

This article incorporates text in the public domain from page 514 of the 20th edition of Gray's Anatomy (1918)