The truncus arteriosus and bulbus cordis are divided by the aorticopulmonary septum. The truncus arteriosus gives rise to the ascending aorta and the pulmonary trunk. The bulbus cordis gives rise to the smooth parts (outflow tract) of the left and right ventricles. [ http://en.wikipedia.org/wiki/Truncus_arteriosus_(embryology) ]

This is just here as a test because I lose it