Did You Know That Ibn al-Nafis Described the Pulmonary Circulation Many Centuries Before William Harvey?

By Shaun Richard McCann

Did you know that Ibn al-Nafis described the pulmonary circulation many centuries before William Harvey (1578-1657)? He was an important figure between Galen (2nd century) and the European scientific Renaissance (16th century) and was part of the Islamic Golden Age. Galen’s teachings prevailed for over one thousand years although many of his anatomical observations were made on animals rather than humans. Galen believed that blood passed from the right side of the heart to the left side via tiny pores in the septum.

Ibn al-Nafis was born near Damascus. He studied medicine at the Nuri Hospital in Damascus but moved to Egypt in 1236 where he spent most of his life. His discussion on Avicenna’s Canon challenges the teaching of Galen and Avicenna (980-1037) and provides the first description of the pulmonary circulation: ‘Blood from the right chamber of the heart must arrive at the left chamber, but there is no direct pathway between them. The thick septum of the heart is not perforated and does not have visible pores as some people thought or invisible pores as Galen thought. The blood from the right chamber must flow through the pulmonary artery to the lungs, spread through its substances, be mingled there with air, pass through the pulmonary vein to reach the left chamber of the heart, and there form the vital spirit…’ He wrote in Arabic before the printing press was invented perhaps resulting in his writings not becoming well known in the West. In 1924 an Egyptian doctor, Muhyo Al-Deen Altawi, discovered a manuscript entitled, Sharh tashrih al-qanun li’ Ibn Sina, or “Commentary on Anatomy in Avicenna’s Canon” in the Prussian State Library in Berlin while studying the history of Arabic Medicine at the medical faculty of Albert Ludwig’s University. This manuscript, by Ibn al-Nafis, contains the earliest description of the pulmonary circulation.

Other people who contributed anatomical observations include Michael Servetus (1511-1553), Vesalius (1514-1564), Realdus Colombus (1516-1587) and Juan Valverde de Amusco (1525-1587). Michael Servetus was convicted of herecy and he and many of his books were burnt.

See West, JB, 1985 and Diramali M et al, 2014