in the 13th century and both proposed that the blood was pushed from the right ventricle to the left via the lungs, however, both of these accounts were largely forgotten. Colombo was the first to propose the pulmonary circuit in an intellectual climate that could expand on his theory. In addition to the pulmonary circuit, Colombo also discovered that the main action of the heart was contraction, rather than dilation, as had previously been thought. Both of these discoveries were later confirmed by William Harvey.

In addition, Colombo