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> That said, da Vinci undertook his own dissections; they led him to make the pioneering discovery that the heart has four chambers. Huh, for some reason I ass

by Macha 3y ago

> That said, da Vinci undertook his own dissections; they led him to make the pioneering discovery that the heart has four chambers. Huh, for some reason I assumed this knowledge would have been older. Like would the romans not have known this? We know they did autopsies. And I mean, various animal hearts have been used in cooking across the world. But wikipedia first cites it to Turkish researchers in the 1200s and spreading to the west in 1400, which is way later I would have expected this kind of visually observable biology knowledge to come from.

pavel_lishin 3y ago
Maybe a sort of chauvinism? Just because animal hearts have four chambers doesn't mean that human hearts do.
- NoMoreNicksLeft 3y ago
  In some instances, there was this "reverse" chauvinism going on. The shape of the human liver was thought to be different for the longest time, I think, because Galen had been dissecting pigs. So while I wouldn't rule out chauvinism entirely, it's anything but a given.
abecedarius 3y ago
Good question. From 100s AD, https://www.researchgate.net/publication/277408882_Galen's_130-201_AD_Conceptions_of_the_Heart https://www.researchgate.net/publication/277408882_Galen's_1... > Galen, like other physicians of his time, knew that the heart had four cavities, but like Erasistratus, he regarded only the ventricles as forming the heart proper and the atria as being a sort of enlargement or bulge of the vessels leading into the ventricles. He points out the presence of four openings in the ventricles, two in each cavity: one to introduce the blood, the other to expel it. The difference between the thick structure of the left ventricle in contrast to the thin of the right impresses him. At the base of the left ventricle, he writes, there is a large hole that comprises three sigmoid membranes and opens into the great artery (aorta), giving rise to all the arteries. He believed wrongly that there was communication between the right and left ventricles because of perforations in the septum, a notion that misled the medical community for centuries Looking up Erasistratus (200s BC), https://oajournals.fupress.net/index.php/ijae/article/download/11661/11091/13056 https://oajournals.fupress.net/index.php/ijae/article/downlo... says > Erasistratus was the first physician who recognized the heart’s activity as a “pump” ... [Ctesibius's] pump consists of two identical cylinders, just like the two heart chambers ... Another great innovation of Erasistratus, was the meticulous description of all four heart valves. It sounds like they were on a good track of research, then progress pretty much stalled until the Turks you mention?
bena 3y ago
It's also quite possible this is knowledge lost and reacquired. Maybe the Romans did know it, but we lost records of them knowing it. And then we subsequently lost the knowledge itself.
tnecniv 3y ago
It might have had to be rediscovered in the West. I remember learning that DaVinci’s autopsies were controversial because they were considered desecrations of someone’s body and therefore disgusting and unholy.

by Macha 3y ago

pavel_lishin 3y ago

Maybe a sort of chauvinism? Just because animal hearts have four chambers doesn't mean that human hearts do.

NoMoreNicksLeft 3y ago
In some instances, there was this "reverse" chauvinism going on. The shape of the human liver was thought to be different for the longest time, I think, because Galen had been dissecting pigs. So while I wouldn't rule out chauvinism entirely, it's anything but a given.

abecedarius 3y ago

Good question. From 100s AD, https://www.researchgate.net/publication/277408882_Galen's_130-201_AD_Conceptions_of_the_Heart https://www.researchgate.net/publication/277408882_Galen's_1... > Galen, like other physicians of his time, knew that the heart had four cavities, but like Erasistratus, he regarded only the ventricles as forming the heart proper and the atria as being a sort of enlargement or bulge of the vessels leading into the ventricles. He points out the presence of four openings in the ventricles, two in each cavity: one to introduce the blood, the other to expel it. The difference between the thick structure of the left ventricle in contrast to the thin of the right impresses him. At the base of the left ventricle, he writes, there is a large hole that comprises three sigmoid membranes and opens into the great artery (aorta), giving rise to all the arteries. He believed wrongly that there was communication between the right and left ventricles because of perforations in the septum, a notion that misled the medical community for centuries Looking up Erasistratus (200s BC), https://oajournals.fupress.net/index.php/ijae/article/download/11661/11091/13056 https://oajournals.fupress.net/index.php/ijae/article/downlo... says > Erasistratus was the first physician who recognized the heart’s activity as a “pump” ... [Ctesibius's] pump consists of two identical cylinders, just like the two heart chambers ... Another great innovation of Erasistratus, was the meticulous description of all four heart valves. It sounds like they were on a good track of research, then progress pretty much stalled until the Turks you mention?

bena 3y ago

It's also quite possible this is knowledge lost and reacquired. Maybe the Romans did know it, but we lost records of them knowing it. And then we subsequently lost the knowledge itself.

tnecniv 3y ago

It might have had to be rediscovered in the West. I remember learning that DaVinci’s autopsies were controversial because they were considered desecrations of someone’s body and therefore disgusting and unholy.