Realdo Colombo was one of the first anatomists in the Western world to describe pulmonary circulation, observing that blood travels between the right and left ventricles of the heart by way of the lungs. Previously, it was believed that blood traveled through a hidden passage (or passages) connecting the ventricles.

Although two other Europeans wrote about this phenomenon around the same time, it was Colombo's book, The 15 Books Written Concerning Anatomy, that directly influenced seventeenth-century anatomist William Harvey's concept of the heart as a pump circulating blood throughout the body.

Son of a pharmacist based in Cremona, Italy, Colombo initially followed his father's trade before undertaking studies in Milan, Venice and then in Padua. Colombo earned his M.D. degree in 1544. At the University of Padua, he studied medicine under another famed anatomist, Andreas Vesalius, eventually becoming his assistant. In 1544, he succeeded Vesalius as lecturer on anatomy and...