Colombo, Matteo Realdo (c. 1516-1559)

Italian anatomist who was the first European to describe pulmonary circulation, the process of blood circulating from the heart to the lungs and back, and oxygenation of the blood.

This showed that Galen's teachings were wrong, and was of help to William Harvey in his work on the heart and circulation. Colombo was a pupil of Andreas Vesalius and his successor as professor of surgery at the University of Padua in 1543. He later became the first professor of anatomy at the University of Padua in 1546. Colombo is also remembered for his ‘discovery’ of the clitoris.

Galen, whose theories had previously been believed infallible, had claimed that blood flowed from the right to the left chambers of the heart through holes in the septum (dividing wall). Vesalius proved that such holes did not exist, but was unable to come up with an alternative. Colombo found a route for the blood from the right ventricle through the pulmonary artery to the lungs, and from the lungs to the left ventricle via the pulmonary vein. He also noticed that, having passed through the lungs, venous blood turned bright red after mixing with the ‘spirit’ of the air.

Although Colombo described the action of the heart, blood being received during diastole (relaxation) and expelled during systole (contraction), he was unable to explain how blood moved around the body. However, further understanding was provided by Geronimo Fabricius, who in 1579 demonstrated that valves in the veins direct blood flow to the heart, and William Harvey, who described the circulatory system in 1628.

Pulmonary circulation was first described by the 13th-century Syrian physician Ibn an-Nafis, whose work was unknown to Europe until 1924.