Hippocrates And Galen's Cardiovascular System

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Ancient Greeks, including Hippocrates and Galen viewed the cardiovascular system as two distinct networks of arteries and veins. The very first conception comes from Erasistratus who believed that arteries and veins were separate. Veins contain blood, while arteries contain air. The portal veins take up food in the intestines, food is then delivered to the liver, transformed into blood and then transported to the vena cava by way of the hepatic vein. He hypothesized that, from the vena cava, venous blood was delivered to all parts of the body. Some of the blood would enter the right ventricle from where it was thought to be diverted to the pulmonary artery to nourish the lungs. In his model, air is taken up in the lungs by pulmonary veins, …show more content…

He was the first person to challenge the classic Galen School convention that blood could pass through the cardiac interventricular system (John B. West, Ibn al-Nafis, the pulmonary circulation, and the Islamic Golden Age). He believed that all the blood that reached the left ventricle passed through the lung and he introduced the concept of capillary circulation by stating there must be small communications or pores between the pulmonary artery and vein. Yet his work remained forgotten until 1924, the discovery of the vascular system is attributed to the English physicist William Harvey who described in 1628 the existence of the systemic circulation and properties of blood being pumped to the brain through physiological experiences led on dogs (De Motus Cordis). This was a major revolution to understand blood circulation (Fig). The presence of valves in the veins cued to the existence of unidirectional blood flow. In Harvey’s conception, the heart drives the mechanics of blood circulation and not the liver. Transfer of blood from arteries to veins in the lung and periphery may occur through direct connections or anastomoses or through porosities in the flesh (the latter mechanism being favored by

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