Blood transfusions were a huge leap forward in the field of medicine. Blood transfusions happen when someone receives blood through an IV into their blood vessels. Thanks to this discovery people can be kept alive longer if not forever. Once we understood how blood circulated throughout the body, the next step was blood transfusions. The first transfusion was carried out in the mid-1600s using animals. It was only a couple of years later when a transfusion was performed on an actual human being and it worked. This breakthrough in medical science has opened up a whole new world for sick or dying people. These blood transfusions not only helped people who were losing blood but also helped cure people suffering from diseases. Blood transfusions are an exceptional creation for the health of human beings and this has produced a huge achievement in the way doctors treat patients. In the early 17th century, people were unsure about how the body's system worked, especially when it came to blood. It wasn't until the mid-1600s that William Harvey discovered how blood circulates throughout the body. Harvey was an English doctor whose discoveries had a great impact on medical science. This discovery completely changed the field of medicine. He was the first to “observe the action of the heart in small animals and fish” (Weisstein). By observing these small animals he concluded about how blood circulates in the bodies. He made many discoveries in which he announced the way the body works and how it uses blood. “He developed the first complete theory of the circulation of blood, believing that it was propelled throughout the body by contractions of the heart” (Weisstein). There were still many gaps in the blood circulation process, but… half of the paper… its days. These men made a tremendous amount of discoveries to bring medicine to where it is today. Works Cited Brown, Theodore M. "Richard Lower." PBS. PBS, 2002. Web. 03 December 2013. Healio. "James Blundell: Pioneer of Blood Transfusion." Healio, January 2009. Web. 03 December 2013. Medical News. "History of blood transfusion". History of blood transfusion. Medical News and Web. 03 December 2013.PMID. "Richard Lower: The Origins of Blood Transfusion." National Center for Biotechnology Information. US National Library of Medicine, 2013. Web. 03 December 2013. Biomedical Scientists. "A Brief History of Blood Transfusion". - The Institute of Biomedical Sciences. IBMS, November 2005. Web. 03 December 2013.Weisstein, Eric W. "Harvey, William (1578-1657) - From the World of Scientific Biography by Eric Weisstein." Harvey, William (1578-1657). World of science, 1996-2007. Network. 03 December. 2013.