Heart Septation During Development

3D Model

Animation showing the septation during heart development.

This model is not true to life; the form and the timing of the events have been exaggerated to illustrate the concepts of septation.

In the first part of the animation, one endocardial cushion can be seen growing into the lumen of the heart tube with the atrial septal components growing to meet it. (The second cushion is not shown.)

In the second part of the animation, the muscular component of the ventricular septum likewise grows to meet the endocardial cushions. Septation of the arterial outflow is first shown as a pair of vertical walls to show how this divides the aorta and pulmonary trunk and assigns each to a separate ventricle. The animation then unwinds this process, and then shows how the septation event occurs not vertically, but spiraling up the vessel to produce an aorta and a pulmonary trunk that are not parallel but rather wind around each other as they leave the heart.

Colors were chosen to be compatible with color-blindness.