Sketch showing blod passing through the Foramen ovale in a fetal heart. The heart has a common pulmonary vein (LV), instead of the four it will have later on in the pregnancy. HF: right atrium, VF: left atrium. Drawn by Kjetil Lenes

I, the copyright holder of this work, release this work into the public domain . This applies worldwide. In some countries this may not be legally possible; if so: I grant anyone the right to use this work for any purpose , without any conditions, unless such conditions are required by law.