bulbus aortae

The bulbus is absorbed into the right ventricle, and its continuation (the truncus) subdivides lengthwise, forming the aorta and the pulmonary artery. The right horn of the sinus venosus is absorbed into the right atrium, together with the superior and inferior venae cavae, which originally drained…

…the conus arteriosus (called the bulbus cordis in embryos), and eventually to the arterial system. The blood is pushed through the heart because the various parts of the tube contract in sequence. As the heart develops from embryo to adult, each part of the tube becomes a chamber, separated from…

…lie above the ventricle and bulbus cordis (embryonic equivalent of the conus arteriosus). Septa gradually partition the heart into chambers.