Segment 1 The narrator gives a brief biography of William Harvey, from his birth to his role as physician to King James I, illustrated with drawings and paintings. In his leisure hours, Harvey pursued his research into the circulation of the blood. The voiceover describes the research done previously by Galen into this subject in the 2nd century, which remained largely uncontested until the 17th century. An animation shows Galen's opinion that food passed into the stomach and intestines, then onto the liver, where it became 'Venus blood', imbued with a 'vital spirit'. He also maintained that the heart had pores, allowing the blood to pass through the chambers. Harvey learnt this version of anatomy at the University of Padua, along with Vesalius' teachings. Time start: 00:00:00:00 Time end: c Length: 00:06:00:22
Segment 2 The University of Padua was renowned for its anatomy teachings. Another teacher there, Fabricius, demonstrated the existence of valves in the veins, and an original painting by Fabricius of valves is shown. Harvey's own research into anatomy and circulation was not based on this learning but rather on dissections and his own observations. Various animal hearts are shown beating, including rabbit, dog, toad, and snake. Harvey soon observed that the heart has two motions that pump blood. Time start: 00:06:00:22 Time end: 00:10:43:05 Length: 00:04:42:12
Segment 3 William Harvey described his experiments in his writings, and these are read out over images of a shrimp's heart, the heart of a chicken embryo and an eel's heart, which is cut open showing blood being forced out of the cut. His experiments also disprove the existence of pores in the heart. Water is shown being injected into the vena cava - no water flows into the other chambers from the right ventricle. Water is then injected into the pulmonary artery and is shown pumping out of a cut in the left ventricle. Harvey writes up his findings in 'De Motu Cordis', stating his hypothesis that blood circulates throughout the whole body. Harvey's work is also the first research that mentions the quantity of blood present in the body. Time start: 00:10:43:05 Time end: 00:16:10:10 Length: 00:05:27:04
Segment 4 Harvey's various experiments are reconstructed, showing that the arteries receive blood through no other way than transmission through the heart. In a snake's heart, the blood flow is stopped below the heart and so the heart receives no blood, meaning that the heart becomes smaller and paler as the blood inside it is pumped out. If the artery above the heart is compressed, the heart swells greatly, as more blood is drawn in but there is no way out for it. Harvey wished also to prove that blood returned to the heart through the veins, but because of lack of magnifying instruments at the time, did not discover capilliaries. He did demonstrate it by looking at the swelling of the veins in a man's arm if it is tied up. Harvey also demonstrated the difference in veins and arteries by cutting them in different parts of the body. Blood is shown shooting out of a rat's artery when it is cut open, 'as if it were coming out of a spout.' Time start: 00:16:10:10 Time end: 00:21:09:10 Length: 00:04:59:00
Segment 5 The next reconstructed experiment demonstrates the valves in veins. A probe is pushed through the vein from one direction but cannot be passed all the way through because the valve stops it; pushed from the other direction its passage is free. Once again a man's arm is tied and swellings appear along the vein, showing the locations of the valves. A finger pushes the blood along the vein, but it cannot be forced beyong the valve. Harvey concludes from his logical arguments and demonstrations that the blood is driven into a round by a circular motion and that it moves perpetually, and that this is the function of the heart. Time start: 00:21:09:10 Time end: 00:27:33:03 Length: 00:06:23:22