Topic > Examining the accuracy of early anatomical discoveries

Throughout history, the discovery of anatomy through the process of dissection has always aroused curiosity in numerous scholars throughout the world's empires. It is interesting to note how dissection has been incorporated into the study of medicine as a science and how this has been influenced by the culture, religion and established beliefs of specific historical periods. The correlation between the process of dissection and the study of anatomy was initially linked incidentally, and its popularity as a science has fluctuated throughout different periods of history. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay In this report, I would like to examine the accuracy of some of the earliest anatomical discoveries that occurred during the pre-medieval period, based on theories developed by scholars such as Hippocrates, Herophilus, and Erasistratus who delved into the study of anatomy through dissection cadaveric to varying degrees and how this affected the accuracy of their studies. I would particularly like to analyze Galen's contribution and legacy to medicine and the study of anatomy, highlighting how his deviation from human cadaveric dissection influenced the vast legacy of his work. I will conclude by recalling how the study of human cadaveric dissection, at the center of anatomical and medical studies, has led to the most important anatomical discoveries that have been able to advance the field of medicine towards the full integration of dissection into the modern medical curriculum. The ancient history of anatomy Hippocrates, the "father of medicine" was born between the Greek and Anatolian peninsula in 460 BC (Persaud, 1984). Although very little of his anatomical studies were correct, given that he based the physiology of the human body on the concept of the four "humors" (Porter, 2017), Hippocrates was the first to eliminate magic and superstition from Medicine and to establish it as a medical science. It is not known whether he carried out dissections of human cadavers as it was considered an "unpleasant if not cruel task" (Persaud, 1984), although he most likely observed wounds and carried out dissections of animals, which allowed him to identify several organs such as lungs, kidneys, urinary bladder and intestines (Persaud, 1984). His most substantial anatomical errors were his more detailed descriptions of the cardiovascular system and the function of the heart's pinnae as air reservoirs (Persaud, 1984). Nonetheless, Hippocratic doctors practiced patient-centred care and were keen observers of disease patterns, skills that modern doctors aspire to acquire and which institutions such as universities and the General Medical Council (GMC) are ensuring are included in the modern curriculum for a degree. of Medicine and Bachelor of Surgery (MBBS). Furthermore, Hippocrates established the concept of “do no harm” or nonmaleficence, now a principle of medical ethics (Porter, 2017). Aristotle, born after the death of Hippocrates, contributed significantly to the knowledge of anatomy despite not being a doctor and not having himself dissected a human corpse (Crowther, 2018). He believed, as many scholars would do after him, that human and animal anatomy were comparable (Persaud, 1984), however he managed to advance the structural presence of large vessels such as the aorta and pulmonary vein and that these arise from heart and not from the brain, as previously believed. His description of the trachea with cartilaginous rings was correct, including its positional relationship to the esophagus and the function of the epiglottis during food ingestion. Aristotle accurately described the gastrointestinal tract, correctly described the porta hepatis through the liver withoutidentify the connection between the hepatic artery and the celiac trunk, the first major branch of the abdominal aorta (Abdel-Misih and Bloomston, 2018). His description of the function of the kidneys as an organ of separation and excretion was correct, although his view of the structure of the kidney as composed of numerous small kidneys (the pyramids) was perhaps a little simplistic (Wallace, 1998). After the fall of Greece to the Roman Empire, scholars of literature and science retreated to Alexandria, the intellectual and cultural center of the world. The rigidity of Aristotelian scholars was overcome by scholars who preferred a more empirical method of study that included scientific investigations, observations and clinical histories. Two prolific individuals in this period were Herophilus of Alexandria and Erasistratus of Ceos, the former considered the founder of systemic anatomy while the latter the first scientific physiologist (Dobson, 1925). As contemporaries and scholars in similar fields of medicine who used the vital tool of cadaveric dissection, their collaboration led to an overall development in the knowledge of anatomy. In Alexandria, cadaver dissection was at the forefront of understanding human anatomy, and both Herophilus and Erasistratus were credited with human vivisection on criminals and with the removal of live fetuses from the womb. Herophilus moved away from Aristotle, providing a description of at least seven pairs of cranial nerves (von Staden, 1992) and realizing that when they emerged from the brain (Porter, 2017), this demonstrated that the brain is the seat of human intelligence, on the contrary of the heart. Although earlier than Galen, Herophilus also suggested that there may be more than seven cranial nerves (Persaud, 1984). Galen had advanced on this point and recognized the importance of tracing the source of all nerves by dissection, which Herophilus had not done. Herophilus and Erasistratus disagreed on the contents of the blood which Herophilus correctly argued was blood while Erasistratus suggested was pneuma (Porter, 2017). Erasistratus was also credited with individual anatomical discoveries that included the function of the bicameral heart as a mechanical pump and illustrated the function of heart valves, which had been discovered by Herophilus (von Staden, 1992). The freedom of their studies of anatomy through dissection and vivisection allowed the Alexandria medical school to further prosper and attract more scholars as their often accurate and empirical findings were repeatable by others eager to gain a truthful understanding of the human anatomy. Therefore the discoveries credited to them are found in the works of eminent later scholars such as Galen since unfortunately all their written works have been lost. Despite the permeating religious and moral impediment, Herophilus and Erasistratus laid the foundations of the study of anatomy on dissection, as previously this was limited to a superficial exploration of the human body triggered by pathological needs rather than for academic purposes (Gosh, 2015 ). The Roman conquest of Alexandria in 30 BC by Octavian, later called Augustus (The Metropolitan Museum of Art, 2000), followed the defeat of Mark Antony and Cleopatra on behalf of the emperor Julius Caesar. The conquest of modern Egypt meant that the dissection of human corpses was no longer permitted (Persaud, 1984). During the period of the Roman Empire that lasted until the invasion of the Sasanian Persians in 619 AD (The Metropolitan Museum of Art, 2000), the infamous scholar Claudius Galen was born. Galen is one of the most famous anatomists of antiquity thanks to his numerous dissections, often public, on different animal species which led to his extensive knowledge of anatomy allowing him to write numerous books on the subject.Galen understood and highlighted to his students the importance of a thorough knowledge of anatomy for the physician. Being named a gladiator by the doctor provided him with the opportunity to observe human anatomy in vivo that he otherwise would not have been able to witness. However, this was not a problem for Galen, who considered the pig's internal organs to be extremely similar to those of a human. What ensured Galen's popularity was that he explained the complexity and exquisite relationship between the structure and function of different parts of the human body as due to divine providence, so it was accepted by all religions and translated into many languages. Galen's studies focused on the dissection of veins, arteries, muscles and nerves. His description of human bones was one of the first to attempt to build an anatomical vocabulary. Although Galen was very meticulous in describing internal organs, his obstinacy in relying on animal dissections led him to make numerous errors. The effect of Galen's legacy on future anatomists meant that his incorrect description of the circulation of the blood, and his adherence to the pneumatic theory established by Erasistratus that the arteries contained pneuma, delayed the discovery of the pulmonary and systemic circulation until the 17th century, when the circulation of the blood was discovered by William Harvey. The Hippocratic theory regarding the four "humors" of the body: blood, phlegm, black bile and yellow bile, was a theory supported by Galen and which described that a state of disease was caused by an imbalance of one of these fluids in the body. He then practiced bloodletting, also known as bloodletting, to cool the body and restore balance in the body. This practice will permeate until the 19th century as well as the theory of "humours". I would argue that although Galen meticulously described many organs of the human body such as the female reproductive system, he partially retreated in relating philosophy and theology so closely to medicine. He despised many of his colleagues who based their studies on empirical findings but then prided themselves on being a medical scientist. Famously, he publicly demonstrated that severing the spinal cord of a living pig at several levels would eventually cause the pig to stop squealing as the recurrent laryngeal nerve was eventually severed (Gross, 1998). This demonstrated the extension of the spinal cord from the brain and that the brain controls behavior (Gross, 1998). However, his errors were based on his personal importance which avoided any variation from his works as well as his explanations of anatomy and physiology through speculations on the macrocosm instead of direct observation and empirical findings. In 1315, the first public human dissection ever recorded was carried out in Bologna by Mondino de' Luzzi (Porter, 2017). Anatomy would become increasingly important in the study of medicine, but it took some time before anatomical theaters were built and anatomical dissection was included in the medical curriculum. Galen's pervasive anatomy and cadaveric dissection were justified as a way to reflect the perfection of the human body created by God rather than to advance clinical practice and surgery based on a more thorough and accurate knowledge of human anatomy. Due to Boniface VIII's papal ban on dismembering bodies in the 1300s (Porter, 2017), the increasing frequency of dissections of corpses can be explained as a growing desire to establish the cause of death after a murder through an autopsy, as well as use dissections as a form of punishment for criminals and at the same time provide entertainment and warning to citizens. Although religious injunctions prohibiting dissection during this period areremained, it is arguable that public apprehension was decisive in ensuring that the practice of dissection was held to rigorous standards (Gosh, 2015). However, it is unlikely that many scholars took advantage of these opportunities to advance the study of anatomy as dissections had now become simply a ritual of demonstrating material known from Galenic texts that would guide the student in his medical education rather than discovery (Porter , 2017). A dissection was then guided by a book with a prereader lecturing from a pulpit while a humble assistant dissected the corpse, with the prereader blindly following the text with an indistinguishable view of the dissected body (Gosh, 2015). It is therefore rational to conclude that the Middle Ages were therefore a period of few anatomical discoveries. Furthermore, it is an era of which we have more simplistic anatomical illustrations than, for example, the Renaissance period. However, it is important to establish that medieval illustrations had a different role, that of simply representing general, non-factual anatomy and being used as teaching aids (Porter, 2017). To whom we can credit the most accurate anatomical illustrations is none other than Leonardo da Vinci, 1452-1519 (Heydenreich, 2017). Leonardo studied anatomy in the most comprehensive way, both from the point of view of a mathematician and from that of an artist. Although Leonardo often relied on tradition rather than observation, for example in describing the liver as five-lobed rather than four-lobed and remaining relatively faithful to Galen, his illustrations were certainly superior and more "realistic" than those of medieval anatomists (Porter, 2017). Leonardo's illustrations convey an in-depth knowledge of the musculoskeletal system without doubts about the exactness of the origin and insertion, as well as a knowledge of the function of muscles and their antagonists and of the complex action of the muscles and bones that act as levers during dynamic movement. As an advance on Erasistratus, Leonardo discovered the movement of the heart valves during systole and diastole and the nature of blood vessels and how they change with age (Keele, 1973). It is surprising that, through his technically advanced experiments, Leonardo failed to discover blood circulation. These successes could not have been achieved without the aid of the true science of dissection and a keen observational eye of Vesalius and Galenism. Overall, the formal study of anatomy by dissection in large European universities such as Bologna and Paris stagnated until the early career of the scholar Andreas Vesalius, born in 1514 (Persaud, 1984). Anatomy teachers were often ignorant of anatomical nomenclature and faithfully followed the Galenic texts, without accepting deviations from his work. Jacob Sylvius, a major influence of Vesalius stated that "man must have changed his structure over time, for Galen's teaching cannot err." However, the brilliant and enterprising Vesalius took his medical education into his own hands, privately dissecting small animals and rodents for his studies. In 1537 Vesalius obtained a degree in Medicine and was appointed professor of Surgery at the University of Padua (Del Negro, 2003; Persaud, 1984). Vesalius was exceptional in the study of anatomy for his redefinition of dissection, often encouraging his students to dissect as he taught and lectured, as well as using the comparative anatomy of small animals to accentuate specific features of the human body. During his professorship at the University, Vesalius correctly articulated a human skeleton and was the first to finally and courageously point out the errorscommitted by Galen in his conclusions drawn by comparing the skeleton of an ape with that of a human being (Persaud, 1984). Vesalius then emphasized the need for cadaver dissection to discover the true anatomy of the human body and suggested that this was the reason behind Galen's numerous unfounded "discoveries". Vesalius brought the process of dissection, previously known as baseless and unpleasant science, back to a level of utmost importance, as the primary tool for pure scientific analysis in the field of medicine. Vesalius clearly received brutal criticism from Galen's supporters but remained unmoved and, unlike Galen, accepted and often responded to his criticism with constructive criticism from colleagues. Vesalius was neither shy nor incapable of making his case, as he pioneered a more dynamic advancement of the science of anatomy, identifying glaring errors in the work of previous scholars simply through scientific experimentation and observation of the human body. Vesalius's primary impact was to move away from the concept that dissection was simply an adjunct to anatomical illustrations and to establish that dissection was essential to learning anatomy (Gosh, 2015). However, Vesalius did not ignore the work of previous scholars and when he published De Humani Corporis Fabrica, 659 pages of illustrated anatomy, in 1543, the book was divided into seven sections, following the Galenic approach to dissection. If his methodology for the dissection process, outlined in the text, had been followed correctly, any aspiring anatomy student could dissect and learn from a human cadaver independently. Despite the more in-depth study of anatomy on human cadavers, Vesalius' work was also intertwined with some erroneous details such as the presence of the "rete mirabile" at the base of the brain, the division of the sternum and the five-lobed liver. This bridge connects Galen to nearly all of his successors, underscoring the impact he had on anatomy despite many of his misconceptions, simply because of the vast legacy he left behind. Vesalius' work would also have this effect and would be considered one of the greatest in modern science since Galen. The 17th century The 17th century brought another advance in the studies of anatomy and medicine, where experimental research was conducted as a means of discovering functional anatomy and physiology, insufficiently studied by all the previously mentioned scholars, Galen, Leonardo and Vesalius . William Harvey, born in 1578, studied at the University of Padua between 1599 and was interested in the study of the movement of blood, inspired by the studies of Aristotle, who maintained that the heart was the origin of the veins and that the organ where all the blood converged. Harvey discovered the function of valves and the direction of flow of venous blood through the simple experiment of pressing and squeezing the swollen veins, but more importantly he applied Galileo's notion of quantitative investigation in biological experiments to discover the circulation of blood. Harvey solved the problem of hemodynamics by measuring that the volume of blood pumped by the heart into the aorta in half an hour is greater than the total volume of blood in the body. Therefore, the blood must be the same as that which is pumped into the body in a circular motion from the heart, through the aorta and throughout the body. Although Harvey's discovery was based on mathematical calculations, he advocated the "modern" method of teaching anatomy through dissection and encouraged students to study and discover anatomy for themselves. (Del Negro, 2003). Conclusion Probably, dissection of human cadavers and comparative anatomy with dissection of small animals are the basis of most.