William Harvey

William Harvey (April 1, 1578 - June 3, 1657) was a medical doctor who is credited with first correctly describing, in exact detail, the properties of blood being pumped around the body by the heart (It should be noted, however, that many of the discoveries he made had already been observed by Ibn Nafis). This developed the ideas of René Descartes who in his Description of the Human Body said that the arteries and veins were pipes and carried nourishment round the body. Many believe he discovered and extended early Muslim medicine especially the work of Ibn Nafis, who had laid out the principles and major arteries and veins in the 13th century.

New circulatory model

He announced his discovery of the circulatory system in 1616 and in 1628 published his work Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus (An Anatomical Exercise on the Motion of the Heart and Blood in Animals), where, based on scientific methodology, he argued for the idea that blood was pumped around the body by the heart before returning to the heart and being recirculated in a closed system.

Related Topics:
1616 - 1628 - Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus

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This clashed with the accepted model going back to Galen, which identified venous (dark red) and arterial (brighter and thinner) blood, each with distinct and separate functions. Venous blood was thought to originate in the liver and arterial blood in the heart; the blood flowed from those organs to all parts of the body where it was consumed. It was for exactly these reasons that the work of the "heathen" Ibn Nafis had been ignored.

Related Topics:
Galen - Liver

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