It is also much more than is needed for nutrition. It must therefore be concluded that the blood in the animal body moves around in a circle continuously and that the action or function of the heart is to accomplish this by pumping. This is only reason for the motion and beat of the heart. Harvey's predecessors and contemporaries believed the blood to be continually formed anew from the digested food, to be dissipated and used up in the tissues, and considered that the primary function of the heart was the production of heat.
Blood was constantly being consumed in the periphery and replenished by ingested nutrients, and this was all carried out by the right ventricle and great veins. Harvey studied the hearts not only of various fishes, amphibian, reptiles, birds, and mammals, but also those of various other animal species. But most important, he not only compared these, he manipulated them in living as well as dead animals.
He isolated parts of the heart; he ligated and divided arteries; he exerted pressure on veins on either side of the valves. His observations of dissected hearts showed that the valves in the heart allowed blood to flow in only one direction.
Harvey measured the volume of the left ventricle and calculated that the amount of blood that passes through the heart of a man in an half hour and established that it was greater than the amount contained in the whole body. Direct observation of the heartbeat of living animals showed that the ventricles contracted together, dispelling Galen's theory that blood was forced from one ventricle to the other.
Dissection of the septum of the heart showed that it contained no gaps or perforations. When Harvey removed the beating heart from a living animal, it continued to beat, thus acting as a pump, not a sucking organ. Harvey also used mathematical data to prove that the blood was not being consumed. Finally, Harvey postulated the existence of small capillary anastomoses between arteries and veins, but these were not discovered until by Marcello Malpighi.
National Center for Biotechnology Information , U. Journal List J Angiogenes Res v. J Angiogenes Res. Published online Sep Domenico Ribatti 1. Author information Article notes Copyright and License information Disclaimer. Corresponding author. Domenico Ribatti: ti. Received Jun 15; Accepted Sep This article has been cited by other articles in PMC. He then tied a ligature on the upper arm of a person, which distended the veins in the forearm and made the valves of the forearm clearly visible.
He tried to force blood in a vein down the forearm, but to no avail. When he tried to push it up the arm, it moved easily. Harvey also believed in witches. At the request of King Charles I, he gladly agreed to examine a suspected witch. The man was not a feminist! National Center for Biotechnology Information , U. Journal List Cardiovasc J Afr v. Cardiovasc J Afr. Gerald Friedland. Author information Copyright and License information Disclaimer. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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