William Harvey is credited with the discovery of the full circulation of blood in the human body, which he first published in 1628 and supported with extensive experiments and arguments.

William Harvey’s Research

Harvey’s crucial work, "Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus" ("Anatomical Exercise on the Motion of the Heart and Blood in Animals"), challenged the long-held Galenic model of blood flow and established that blood circulates rapidly and continuously in a closed system powered by the heart. He proved venous valves direct blood back to the heart and calculated blood flow volumes that made tissue absorption impossible, supporting his circulation theory.

Earlier Insights and Contributors

Prior to Harvey, partial ideas about blood movement had been proposed. For example, the Spanish physician Michael Servetus and others described pulmonary circulation, and Ibn al-Nafis hinted at similar concepts in the 13th century, but a complete understanding was not reached until Harvey’s experimental approach. Harvey differed by demonstrating the full circuit—arteries, veins, and the role of the heart in pumping blood throughout the body.

Lasting Impact

Harvey’s work revolutionized medicine, shifting therapies and expectations by replacing old beliefs with a scientific model of cardiovascular function. His discoveries marked the birth of modern physiology and experimental medicine.

In summary, while earlier contributors made important observations, William Harvey is recognized as the scientist who discovered and proved the full circulation of blood.