Leonardo’s studies in anatomy provide remarkable insights into the inner workings of a passionate learner. Granted, it is only one of a seemingly infinite number of topics that Leonardo delved into during his lifetime. That being said, his anatomy studies in particular are instructive as a microcosm of his life and career – his background, his motivations, and even his shortcomings.

As with many of his elaborate research expeditions, Leonardo’s goal in studying anatomy was to inform his hyper-realistic portrayals of human beings. Driving this obsession was Leonardo’s belief that “an artist should build a picture of a human body from the inside out, first conceiving of the skeleton, then the skin, then the clothing” (p. 77). Even his anatomy notes could be considered works of art, with figures so carefully drawn and shaded that one forgets these are drawings at all. Leonardo paid special attention to the cranial nerves, those which control the muscles of the face. He meticulously mapped these nerves to their adjoining muscles, all the while trying to understand how the brain converted emotions into facial expressions. Who other than Leonardo would study such a topic, the man who would go on to craft the famously mysterious smile of the Mona Lisa?

Leonardo’s extensive anatomy studies, combined with his propensity to go down rabbit holes of his own curiosity, led him to a great number of discoveries and insights about the human body. Isaacson makes special mention of one such rabbit hole, namely Leonardo’s aortic valve studies. In these studies, Leonardo pondered how the aortic valve, the gateway to the body’s main artery, closed after each subsequent beat of the heart. He rejected the widely held notion that the aortic valve closes from a simple backflow of blood, which is how most valves work. Rather, he realized that it was the recurrent formation of a mini-vortex above each of the valve’s leaflets which mediated the valve’s closure. This finding would be confirmed over 400 years later by British researchers at Oxford, using radiographic techniques.

Perhaps what is most remarkable about Leonardo’s explorations in anatomy was his lack of a formal education in any field, let alone science and medicine. Leonardo self-studied through experiments and textbooks, and he scoffed at his peers who tried using their credentials as a symbol of knowledge or status. How much harder might Leonardo have scoffed at the astronomical price of such status today, with medical students in the United States paying upwards of $300,000 to become society’s bona fide experts in human anatomy! Medicine, of course, is farther reaching than anatomy alone. Yet it would behoove us to appreciate what can be accomplished with not much more than a healthy dose of curiosity.

The sheer volume of Leonardo’s contributions to anatomy begs the question of why Leonardo has not gotten his due in anatomy textbooks and medical education worldwide. Why do we read Gray’s Anatomy, and not “da Vinci’s Anatomy”? Sadly, Leonardo’s voracious appetite for knowledge was a double-edged sword in this regard. Leonardo’s intense focus during his years of study left little time for other activities, least of all organizing his findings into cohesive papers and textbooks. Isaacson said it best when he wrote that Leonardo “did not seem to realize or care that the importance of research comes from its dissemination” (p. 423). As a result, much of Leonardo’s work was either discovered long after his death, or lost in the mists of time altogether. This remains a blemish on an otherwise fruitful career, but even for this, I’m inclined to give him a pass – after all, he was only human.