Leonardo da Vinci – who died 500 years ago today – drew uncannily accurate studies of the human body. And if had been published in his lifetime, they would have changed the course of science, says Alastair Sooke

One day, probably during the winter of 1507-08, Leonardo da Vinci found himself chatting with an old man in the hospital of Santa Maria Nuova in Florence. Sitting on a bed, the man revealed that he felt nothing wrong with his body other than weakness, despite being more than 100 years old. “And thus,” Leonardo recorded, “without any movement or sign of any mishap, he passed from this life.

“And I dissected him to see the cause of so sweet a death.”

It was not the first time that Leonardo had sliced into a corpse: by 1508, by his own reckoning, he had conducted more than 10 human dissections. Nine years later, this tally had risen above 30. But his study of the cadaver “del vechio” (“of the old man”), as Leonardo called him, rekindled his long-held obsession with the structure of the human body.

In the years that followed, the pre-eminent polymath of the High Renaissance embarked on arguably the most exhaustive and insightful campaign of anatomical investigation ever waged in the history of medical science. The fruits of this research, a series of 18 mostly double-sided sheets known collectively as the Anatomical Manuscript A, overflow with more than 240 meticulous drawings as well as 13,000 words of notes written in his idiosyncratic “mirror-script”.