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Journal of Postgraduate Medicine, Vol. 48, Issue 3, 2002 pp. 242 Looking Back The Flow of Life Deshpande AV Department of Paediatric Surgery, Seth GS Medical College and KEM Hospital, Parel, Mumbai - 400012, India. Code Number: jp02084 The sight of flowing blood is a terrifying one indeed, but it is a flow of life. William Harvey is famous for his discovery of human circulation. But surprisingly it was not this great Briton who was the first to realize that blood flows. So then, how did we learn of the flow of blood and what was Harvey's contribution? Long, long ago since the times of Aristotle, it was known that the blood flows. Galen proved that the arteries contained blood and not air. He also professed that there were anastomoses between the arteries and the veins, a fact that Harvey refused to accept! Cesalpinus described two closed systems of circulation, one arising from the liver and supplying the body and the other involving the heart and the lungs enriching the spirit. But sadly, however accurate these descriptions appeared, they were mere speculations. They emerged from the occasional observations of the 'arm-chair' philosophers. Then came the people of action, Harvey being the most famous. William Harvey, one of the greatest names in experimental science, was born in Folkstone in 1578. He attended Granville and Caius Colleges, Cambridge and then proceeded to Padua, the greatest contemporary college of Anatomy. He was trained by Fabricius who was a great Anatomist himself. Fabricius had described the valves in the veins and the development of the chick embryo. Harvey was deeply influenced by the teachings and the methods of Fabricius, and he admitted to have thought of the direction of circulation based on the description of valves by Fabricius. Harvey returned to England and joined the Royal College of Physicians in London. He started working on the problem of circulation. No one before his day had attempted such an elaborate experimental work deliberately planned to solve the problem relating to the single most function of the body. In 1616, he delivered a famous lecture in which he presented his concepts of circulation. The accuracy and vividness of Harvey's description of the motion of the heart have been appreciated by generations of physiologists. His thoughts, however, were looked upon coldly by his colleagues. Harvey continued with his noble mission. In 1628, Harvey published a small volume titled 'De Motu Cordis' in Frankfurt. He wrote on the function of the heart and the transmission of blood through the vessels. The movement of the heart was for a long time thought to be beyond human understanding, but Harvey analysed it perfectly. He wrote that the apex impulse occurred during the contraction of the heart; the contraction of the heart was brought about by the contraction of the muscle fibres and this contraction resulted in forceful expulsion of the blood from the ventricles. This laid a sound basis for the discovery of the circulation. Harvey went on and established the pulse to be the column of expelled blood, and that valves ensured the direction of flow in the veins and that human circulation was indeed a complete circle! His experiments were neat and convincing although they were not accepted immediately. On the solid foundation of his work generations of medical men have developed the science and medicine of the circulatory system. William Harvey achieved much in his lifetime. He was the physician to Charles I of England. He was elected to the post of President of College of Physicians, which he declined due to old age. Before his death this great doctor gave all his estate to the college. But the greatest achievement of William Harvey is the fantastic use of his anatomical knowledge to discover the physiology of circulation _ a wonderful coming together of sciences!
Deshpande AV Department of Paediatric Surgery, This article is also available in full-text from http://www.jpgmonline.com/ © Copyright 2002 - Journal of Postgraduate Medicine |
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