"Dr Torrent-Guasp... formalized this description by indicating that the heart looked like a "rope"... [in] three parts: a beginning and an end at the and ; a wraparound loop called a basal loop; and... a helix that he called the apical loop. ...He described a [billion year old] worm... with a vascular tube... like a rope, with a venous and an arterial system. ...[F]ish evolved to show the first generation of a heart, containing a single pumping chamber, and included gills... [Next] the amphibian and the reptile appeared, in which we observe an atrium and a ventricle. Each chamber was separated by an atrial and ventricular septal defect. Human beings developed... [later] and both the atrial defect and the ventricular defect are closed."