The prominent jugular vein in the neck of Michelangelo's David reveals that the sculptor knew certain details of the circulatory system a century before doctors. On most sculptures and living people, the jugular vein is not normally visible. Yet in the Renaissance master's work — displayed in the Galleria dell'Accademia di Firenze in Italy — the vein is swollen and visible above David's collarbone.

Such a feature would be anatomically realistic, given that the sculpture depicts the biblical hero in a state of excitement, about to battle the Philistine giant, Goliath. Notable, however, is that Michelangelo appears to have associated a swollen jugular with physical excitement 124 years before this was documented by medical science. This connection appears to have only just been spotted now, however — 515 years after the Italian artist finished sculpting his famous work.