Ibn al Nafis: The discovery of human blood circulation in the 13th Century

Ibn al Nafis (Ala ad-Din Abu al Hasan Ali Ibn Abi-Hazm al Qarsh) was a Muslim polymath known as the father of Circulatory Physiology. He is considered to be the first to describe the pulmonary circulation of the blood, although the Western educational institutes attribute that discovery to the 17th-century English scientist William Harvey. 

Ibn al Nafis was a versatile thinker, making immense contributions to various fields such as politics, anatomical studies and jurisprudence. Despite his fame in ophthalmology, and performing several human dissections, his extensive work on pulmonary circulation stands out in the field of science. 

The 13th-century thinker also gave an early insight into the coronary and capillary circulations.

The early studies on heart and anatomy of circulation first started in 500 BC with observations of Alcmaeon of Croton about the arteries and veins in animal dissections. His studies were confirmed by Herophilus of Chalcedon in 300 BC during cadaver studies. Then, Aristotle described the heart as a three-chambered organ in 350 BC.

Before Ibn al Nafis, Greek Physician Galen claimed that there was no passage in the septum and believed that the circulation system originated from the liver. He also though that although blood passed through invisible pores in the interventricular septum from right to left, venous and arterial systems were two separate closed systems, the theory which had existed since the 2nd Century AD.

Ibn al Nafis was the first to contradict Galen's theory by describing the flow of blood between heart and lungs correctly. He also described the interventricular septum as a non-porous wall that is impermeable to blood. Therefore, Ibn al Nafis adopted the concept of pulmonary circulation as the only way for blood to pass between the two sides of the heart.

As a devout Muslim and physician, he contributed visibly much to the body of knowledge in anatomy and medicine. Hence, today scholars are able to find the first description of coronary vessels and the correct definition of the blood supply of the heart likewise the correct description of the pulmonary circulation.

All his discoveries spread across the world and were translated into Latin by Andreas Alpagus and appeared in the works of various European scholars from Servetus to Harvey.

Ibn al Nafis wrote many books in medicine but ‘Sharah al Tashreeh al Qanoon’ (‘Commentary on the anatomy of the Canon of Avicenna’) has been the most famous amongst his works. 

The book was forgotten until the time when Egyptian physicians discovered a manuscript with the title ‘Commentary on the anatomy of the Canon of Avicenna’ in the Prussian state library in Berlin, Germany, in 1924. 

Commentary on the anatomy of the Canon of Avicenna (Ibn Sina) contains the first description of the pulmonary circulation by explaining:

• Blood from the right chamber of the heart to the left chamber does not come through the direct pathway.
• The interventricular septum does not have visible or invisible pores.
• “The lungs are composed of parts, one of which is the bronchi, the second the branches of the arteria venosa and the third the branches of the vena arteriosa, all of them connected by loose porous flesh.”
• Blood from the right chamber of the heart goes to -vena arteriosa (pulmonary artery) - lungs - arteria venosa (pulmonary vein) - left chamber (here the vital spirit is formed).
• “Ibn Sina’s (Avicenna) statement that the blood that is in the right side nourishes the heart is not true at all, for nourishment of the heart is actually from the blood that goes through the vessels that permeate the body of the heart.
  
  

The Origins
Ala ad-Din Abu al Hasan Ali Ibn Abi-Hazm al Qarshi, known as Ibn Nafis Damishqi, was born in a small town near Damascus called Qarsh in 1210. 

In his early life, he studied theology, philosophy and literature. When he turned 16, he started studying medicine, which lasted 10 years at the hospital in Damascus, founded by the Turkish prince Nureddin Mahmud Zengi in the 12th Century.

In 1236, Ibn al Nafis and his colleagues moved to Egypt following the request of the  Ayyubid sultan al Kamil. He first appeared as the chief physician at al Naseri hospital which was founded by Saladin the victor where he practised medicine for several years. 

He mostly spent his life in Egypt and witnessed massive incidents like the fall of Baghdad and the rise of Mamluks. He became the personal physician of many leaders such as Sultan Baibars. 

At the age of 74, Ibn al Nafis became the chief physician of the newly founded al Mansori hospital where he worked there until the end of his life. He died in Cairo following. Prior to his death, Ibn al Nafis donated his entire library and house to Qalawun Hospital.