Do right and left seem backward? That's because you're looking at an illustration of somebody else's heart. To think about how your own heart works, imagine wearing this illustration on your chest.

Instead, Vinken shows us that the earliest known rendering of a heart is a Mesoamerican human effigy vessel ... in the subtleties of cardiac anatomy. In fact, Vinken artfully hypothesizes that ...

subtle but crucial differences in heart anatomy and function have emerged in response to unique environmental challenges.

In the Step Thru below, see the complicated path the blood takes as it moves in and out of the heart. Do right and left seem backward? That's because you're looking at an illustration of somebody ...