Blood Circulation🩸

Invention/Contribution:

• The first correct description of pulmonary blood circulation (the flow of blood from the heart to the lungs and back) was made by Ibn al-Nafis (1213–1288, Damascus & Cairo).

• In his commentary on Avicenna’s Canon of Medicine, he refuted Galen’s theory that blood passed through invisible pores in the heart.

• Instead, Ibn al-Nafis explained that blood moves from the right ventricle to the lungs, is purified, and then flows to the left ventricle.

• His work remained unknown in Europe until rediscovered in the 20th century, long before William Harvey’s famous description in the 17th century.

Why it matters:

• Ibn al-Nafis is now recognized as the “Father of Pulmonary Circulation.”

• Showed the importance of observation and challenging ancient authority with new evidence.

• His discovery paved the way for modern cardiology and medicine.

“The blood from the right chamber of the heart must arrive at the left chamber, but there is no direct pathway between them… the blood must pass through the lungs.” 

Ibn al-Nafis, Commentary on the Canon (13th century)

In the 13th century, long before Europe’s William Harvey, a Muslim physician named Ibn al-Nafis discovered how blood really circulates. He described the flow of blood from the heart to the lungs and back, overturning Galen’s ancient errors. His insight made him the Father of Pulmonary Circulation, a milestone in medicine that shows how Muslim scholars advanced science through observation, courage, and discovery.