What do we know about the structure of the heart? Well, the first thing is that the heart is not “heart-shaped”—as in Valentine’s Day heart-shaped. I know this seems obvious, but I can still remember the day in anatomy class when I was slightly taken aback to discover that there was nothing about the heart in front of me that resembled a Valentine’s Day heart.
Of course, I’d seen beautiful images of organs in anatomy books, so I also half- expected to find a clearly outlined, well-defined organ in front of me. Instead, the heart in front of me looked like a lump of tissue. Not an organ, just tissue—a muscle, embedded in fat. Nonspecific, nondescript fat. I hid my disappointment, but a little part of me felt crushed. The heart was nothing special.
While in medical school, I learned that the heart is made out of a special kind of intermediate muscle (shared only by the uterus in the human body), that it has four valves each with its own set of “leaflets,” and that each of the heart’s four chambers— two upper atria and two lower ventricles—have a different thickness. We went on to examine the pressures and some aspects of the flow of blood entering and leaving the heart. But nothing was said about the actual shape of the heart. Or any other organ. This was simply not a matter of interest.
This lack of attention paid to the structure of the heart surprises me now because humans have a rich history of fascination with the human form and the geometry of the natural world. We see this in the depiction of people and various animals as a series of triangles and circles in ancient cave paintings. And we also see it in the writing of the ancient Greeks, especially that of Plato, who believed that the five Platonic solids—tetrahedron, cube, octahedron, dodecahedron, and icosahedron—were the basis of all natural phenomena, including of the human form.
The following excerpt is from Dr. Cowan’s book
(Chelsea Green Publishing, November 2016) and is reprinted with permission from the publisher.