Post by Sayed Shakar Abbas

In the early 17th century, human understanding of the circulatory system hadn’t changed much since the time of Galen. Among medical professionals the commonly held belief was that blood was created in the liver from food, then it flowed to the heart to be heated, and was afterwards pushed out into the veins by the lungs. William Harvey was the royal physician in the court of James I. Educated at the University of Padua in Italy and at Cambridge, Harvey developed a reputation as an expert in human anatomy and before coming to the court he had given anatomy lectures and dissection demonstrations to the Royal College of Physicians for several years. In the course of his studies Harvey became convinced that the prevailing theories on blood circulation were all wrong. In 1628 he published “Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus” (“Anatomical Account of the Motion of the Heart and Blood in Animals”), an extensive treatise on what we now call the circulatory system. According to Harvey, the heart didn’t heat blood, rather it pumped it into the arteries. He correctly surmised, without specifically identifying capillaries, that blood coursed throughout the body before being returned to the heart via the veins. Harvey nailed it, and his discovery was essential to the development of modern medicine. But instead of earning him praise and gratitude, Harvey’s work was dismissed and ridiculed by the medical establishment. It took twenty years before his theories regarding blood circulation were generally accepted. William Harvey died in London at age 79 on June 3, 1657, three hundred sixty-nine years ago today. He had no children and left most of his estate to the Royal College of Physicians.