The need of the lung for the vena arteriosa is to transport...

The need of the lung for the vena arteriosa is to transport to it the blood that has been thinned and warmed in the heart, so that what seeps through the pores of the branches of this vessel into the alveoli of the lung may mix with what is of air therein and combine with it ... and the mixture is carried to the left cavity of the heart by the arteria venosa" (Haddad 1936). Ibn-El-Nafis also made other contributions in the circulation.

Avicenna, following Galen's description of the anatomy, stated that the human heart has three ventricles.

Ibn-El-Nafis rejected that as he said "...And his statement ((Avicenna's) that the heart has three ventricles is not correct, as the heart has only tow ventricles..." He was also the first to describe the coronary circulation as he wrote "...Again, his statement (Avicenna's) that the blood in the right side is to nourish the heart is not true at all, for the nourishment of the heart is from the blood that goes through the vessels that permeate the body of the heart...

" Three centuries after the discovery of the pulmonary circulation by Ibn- El-Nafis, others, such as Michael Servetus, Realdus Colombus, Carlo Ruini, Andrea Cesalpino, and Francois Rabelais, claimed the same thing (Mayerhof 1935). There is a strong suspicion that these authors obtained their knowledge from the Arabic literature which was available at that time to the European investigators without giving credit to Ibn-El-Nafis (Keys 1971, Haddad 1942).

It is considered to be more than a coincidence that Servetus would discover the pulmonary circulation, and also to write a book, similar to that of Ibn-El-Nafis, on Unitarianism. Servetus was burnt with his book, "Restitutio Christianismi" in Geneva in October 1553 at the order of Calvin because he was considered heretic. Previous…