Ancient Rome’s most notorious doctor - Ramon Glazov

3,057,576 views ・ 2019-07-18

TED-Ed


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In the middle of the 16th century,
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a talented young anatomist named Andreas Vesalius made a shocking discovery:
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the most famous human anatomy texts in the world were wrong.
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They not only failed to account for many details of the human body,
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they also described the organs of apes and other mammals.
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While Vesalius knew he was right,
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announcing these errors would mean challenging Galen of Pergamon–
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the most renowned physician in medical history.
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But who was this towering figure?
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And why did doctors working more than 1,300 years later so revere and fear him?
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Born in 129 CE,
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Galen left home as a teen to scour the Mediterranean for medical wisdom.
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He returned home a gifted surgeon with a passion for anatomy
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and a penchant for showmanship.
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He gleefully entered public anatomy contests,
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eager to show up his fellow physicians.
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In one demonstration,
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he caused a pig to lose its voice by tying off one of its nerves.
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In another, he disemboweled a monkey and challenged his colleagues to repair it.
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When they couldn’t, he did.
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These grizzly feats won him a position as surgeon to the city’s gladiators.
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Eventually, he would leave the arena to become the personal physician
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to four Roman Emperors.
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While his peers debated symptoms and their origins,
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Galen obsessively studied anatomy.
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He was convinced that each organ had a specific function.
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Since the Roman government largely prohibited working with human cadavers,
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Galen conducted countless dissections of animals instead.
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Even with this constraint,
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his exhaustive investigations yielded some remarkably accurate conclusions.
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One of Galen’s most important contributions
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was the insight that the brain, not the heart, controlled the body.
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He confirmed this theory by opening the cranium of a living cow.
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By applying pressure to different parts of the brain,
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he could link various regions to specific functions.
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Other experiments allowed him to distinguish sensory from motor nerves,
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establish that urine was made in the kidneys,
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and deduce that respiration was controlled by muscles and nerves.
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But these wild experiments also produced extraordinary misconceptions.
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Galen never realized that blood cycles continuously throughout the body.
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Instead, he believed the liver constantly produces an endless supply of blood,
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which gets entirely depleted on its one-way trip to the organs.
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Galen is also credited with solidifying the popular theory of the Four Humours.
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Introduced by Hippocrates centuries earlier,
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this misguided hypothesis attributed most medical problems
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to an imbalance in four bodily fluids called humours.
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To correct the balance of these fluids, doctors employed dangerous treatments
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like bloodletting and purging.
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Informed by his poor understanding of the circulatory system,
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Galen was a strong proponent of these treatments,
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despite their sometimes lethal consequences.
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Unfortunately, Galen’s ego drove him to believe that
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all his discoveries were of the utmost importance.
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He penned treatises on everything from anatomy to nutrition to bedside manner,
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meticulously cataloguing his writings to ensure their preservation.
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Over the next 13 centuries,
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Galen’s prolific collection dominated all other schools of medical thought.
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His texts became the standard works taught to new generations of doctors,
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who in turn, wrote new essays extolling Galen’s ideas.
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Even doctors who actually dissected human cadavers
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would bafflingly repeat Galen’s mistakes,
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despite seeing clear evidence to the contrary.
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Meanwhile, the few practitioners bold enough to offer conflicting opinions
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were either ignored or ridiculed.
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For 1,300 years, Galen’s legacy remained untouchable–
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until renaissance anatomist Vesalius spoke out against him.
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As a prominent scientist and lecturer,
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his authority influenced many young doctors of his time.
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But even then, it took another hundred years
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for an accurate description of blood flow to emerge,
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and two hundred more for the theory of the Four Humours to fade.
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Hopefully, today we can reap the benefits of Galen’s experiments
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without attributing equal credence to his less accurate ideas.
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But perhaps just as valuable
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is the reminder that science is an ever-evolving process,
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which should always place evidence above ego.
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