The aorticopulmonary septum (also called the spiral septum, or aortic septum in older texts) is developmentally formed from neural crest

Neural crest

Neural crest cells are a transient, multipotent, migratory cell population unique to vertebrates that gives rise to a diverse cell lineage including melanocytes, craniofacial cartilage and bone, smooth muscle, peripheral and enteric neurons and glia....

, specifically the cardiac
neural crest, and actively separates the aorta

Aorta

The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...

 and pulmonary arteries

Pulmonary artery

The pulmonary arteries carry deoxygenated blood from the heart to the lungs. They are the only arteries that carry deoxygenated blood....

 and fuses with the interventricular septum

Interventricular septum

Interventricular septum , abbreviated IVS, is the stout wall separating the lower chambers of the heart from one another....

 within the heart

Heart

The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

 during development.

The actual mechanism of septation of the outflow tract is poorly understood, but is recognized as a dynamic process with contributions from contractile, hemodynamic

Hemodynamics

Hemodynamics, meaning literally "blood movement" is the study of blood flow or the circulation.All animal cells require oxygen for the conversion of carbohydrates, fats and proteins into carbon dioxide , water and energy in a process known as aerobic respiration...

, and extracellular matrix

Extracellular matrix

In biology, the extracellular matrix is the extracellular part of animal tissue that usually provides structural support to the animal cells in addition to performing various other important functions. The extracellular matrix is the defining feature of connective tissue in animals.Extracellular...

 interactions. Malalignment of the septum can cause the congenital heart condition Tetralogy of Fallot

Tetralogy of Fallot

Tetralogy of Fallot is a congenital heart defect which is classically understood to involve four anatomical abnormalities...

.

External links

• http://isc.temple.edu/marino/embryology/Heart98/abnorm_text.htm