Hi. Our present unit is on the heart, problems, etc. The professora wants us to trace the path of a drop of blood through the heart, from the superior and inferior vena cava to the aorta. Can someone please simplify this for me in a 1.2.3. manner. I know this is asking a lot, but I'd really appreciate it. It seems that every search I do goes off track. What is the big mystery? I know the parts. Or a good reference would help too. Thanking you very much in advance.