4.+Medicine

Marjorie, Nicole, Joelle, Laura

** Timeline of Key Events **
 * Early 1500s **, Paracelsus, a Swiss physician, experimented with chemistry and disproved // Galen // ’s idea that chemical changes, as such, transforming one substance into another was impossible (Galen hypothesized that diseases was caused by the imbalance of the four bodily humors: blood, yellow bile, phlegm, black bile)


 * 1543 **, // Andreas Vesalius // , a professor of anatomy wrote a book “On the Fabric of the Human Body” in which he made accurate drawings of human anatomy by personally dissecting a body. He corrected some of Galen’s errors, by proving that blood vessels originate from the heart and not the liver.

// (Building on Vesalius’s book, a French physician, Ambroise Pare developed an ointment that could be applied to wounds to prevent infection instead of the traditional method of pouring boiling oil on it. He later developed a technique to close wounds with stitches.) //


 * 1590 **, a Dutchman // , // // Zacharias Janssen // produced a compound microscope employing a double convex and a double concave lens. His microscopes had a maximum magnification of only 9X, with images being somewhat blurry, but they paved the way for the development of better microscopes.


 * 1600s **, // Antony van Leeuwenhoek // built microscopes that magnified over 200 times, with clearer and brighter, allowing for the observation of many more micro-organisms.


 * Early 1600 **, Galileo had invented a simple thermometer


 * 1628 **, // William Harvey // , a London physician, announced his theory that blood circulated continuously in the body and published his theories in a book entitled 'Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus' ('An Anatomical Study of the Motion of the Heart and of the Blood in Animals'), where he explained how the heart propelled the blood in a circular course through the body. (He had found a way of measuring the amount of blood pumped by the heart and it was obvious that the body could not possibly manufacture all the blood that was being pumped. It had to be continuously recirculated.)


 * 1661 **, Marcello Malpighi, discovered capillaries in the lungs of a frog, explaining how the blood flowed from arteries into veins, hence proving Harvey’s work.


 * 1700s **, doctors in Europe learnt how to produce a vaccine that could be used to prevent smallpox, through the research of Edward Jenner.


 * 18th century **, Leeuwenhoek discovered sperm and bacteria with his microscope.

bacterial cause for decay.
 * 18th century **, Swammerdam dissected insects and discovered the


 * 18th century **, Athanasius Kirchner, a Jesuit, discovered microorganisms in the blood of plague victims, and stated that the transfer of noxious organisms from one person to another was the cause of infectious disease.

** Biographical Write Ups ** ** __Galen__ ** (September AD 129 – 199/217) Claudius Galenus of Pergamum (131-201 AD), better known as Galen, was a physician, writer and philosopher who became the most famous doctor in the Roman Empire. His views dominated European medicine 1,500 years.

Claudius Galen was born in Pergamum (modern-day Turkey) of Greek parents. He studied in Greece, in Alexandria and other parts of Asia Minor. His father, the architect Nicon, is supposed to have prepared Galen for a career in medicine following the instructions given him in a dream by the god of medicine, Asclepius. Accordingly, Galen studied philosophy, mathematics, and logic in his youth and then began his medical training at age sixteen at the medical school of Pergamum attached to the local shrine of Asclepius. At age twenty, Galen embarked on extensive travels, broadening his medical knowledge with studies at Smyrna, Corinth, and Alexandria. At Alexandria, the preeminent research and teaching center of the time, Galen was able to study skeletons (although not actual bodies).

Returning to Pergamum at age twenty-eight, Galen became physician to the gladiators, which gave him great opportunities for observations about human anatomy and physiology. In 161 A.D., Galen moved to Rome and quickly established a successful practice after curing several eminent people, including the philosopher Eudemus. Galen also conducted public lectures and demonstrations, began writing some of his major works on anatomy and physiology, and frequently engaged in polemics with fellow physicians. In A.D. 174, Galen was summoned to treat Marcus Aurelius and became the emperor's personal physician.

Galen once again returned to Pergamum in A.D. 166, perhaps to escape the quarreling, perhaps to avoid an outbreak of plague in Rome. After a few years, Galen was summoned back to Rome by Marcus Aurelius. He became physician to two subsequent emperors, Commodus and Septimius Severvs, and seems to have stayed in Rome for the rest of his career, probably dying there in about A.D. 199. Galen was an astonishingly prolific writer, producing hundreds of works, of which about 120 have survived. His most important contributions were in anatomy. Galen expertly dissected and accurately observed all kinds of animals, but sometimes mistakenly--because human dissection was forbidden--applied what he saw to the human body. Nevertheless, his descriptions of bones and muscle were notable; he was the first to observe that muscles work in contracting pairs. He described the heart valves and the structural differences between arteries and veins. He used experiments to demonstrate paralysis resulting from spinal cord severing, control of the larynx through the laryngeal nerve, and passage of urine from kidneys to bladder. An excellent clinician, Galen pioneered diagnostic use of the pulse rate and described cardiac arrhythmias. Galen also collected therapeutic plants in his extensive travels and explained their uses.

In his observations about the heart and blood vessels, however, Galen made critical errors that remained virtually unchallenged for 1,400 years. He correctly recognized that blood passes from the right to the left side of the heart, but decided this was accomplished through minute pores in the septum, rather than through the pulmonary circulation. Like Erasistratus, Galen believed that blood formed in the liver and was circulated from there throughout the body in the veins. He did show that arteries contain blood, but thought they also contained and distributed pneuma, a vital spirit. In a related idea, Galen believed that the brain generated and transmitted another vital spirit through the (hollow) nerves to the muscles, allowing movement and sensation.

After Galen, experimental physiology and anatomical research ceased for many centuries. Galen's teachings became the ultimate medical authority, approved by the newly ascendant Christian church because of Galen's belief in a divine purpose for all things, even the structure and functioning of the human body. Most of Galen's Greek writings were first translated to Syriac by Nestorian monks in the university of Jundi Shapur, Persia. Then Muslim scholars translated them to Arabic, alongside many other Greek classics. They became one of the main sources for Persian scholars such as Avicenna and Rhazes.The medical world moved on from Galenism only with the appearance of Andreas Vesalius's work on anatomy in 1543 and William Harvey's work on blood circulation in 1628.

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__**Andreas Vesalius**__ (December 31, 1514 - October 15, 1564)

Andreas Vesalius was born on 31 December 1514 in Brussels, Belgium, then part of the Holy Roman Empire. He came from a family of physicians and both his father and grandfather had served the holy Roman emperor. Vesalius studied medicine in Paris but was forced to leave before completing his degree when the Holy Roman Empire declared war on France. He then studied at the University of Louvain, and then moved to Padua to study for his doctorate. Upon completion in 1537 he was immediately offered the chair of surgery and anatomy.

Surgery and anatomy were then considered of little importance in comparison to the other branches of medicine. However, Vesalius believed that surgery had to be grounded in anatomy. Unusually, he always performed dissections himself and produced anatomical charts of the blood and nervous systems as a reference aid for his students, which were widely copied. In the same year Vesalius wrote a pamphlet on bloodletting, a popular treatment for a variety of illnesses. There was debate about where in the body the blood should be taken from. Vesalius' pamphlet was supported by his knowledge of the blood system and he showed clearly how anatomical dissection could be used to test speculation, and underlined the importance of understanding the structure of the body in medicine.

In 1539, his supply of dissection material increased when a Paduan judge became interested in Vesalius' work, and made bodies of executed criminals available to him. Vesalius was now able make repeated and comparative dissections of humans. This was in marked contrast to Galen, the standard authority on anatomy who, for religious reasons, had been restricted to animals, mainly apes. Vesalius realised that Galen's and his own observations differed, and that humans do not share the same anatomy as apes.

In 1543, Vesalius published 'De Humani Corporis Fabrica' ( **// On the Fabric of the //****// Human Body) //**. The book was based largely on human dissection, and transformed anatomy into a subject that relied on observations taken directly from human dissections. Vesalius now left anatomical research to take up medical practice. Maintaining the tradition of imperial service, he became physician to the imperial court of Emperor Charles V and in 1555 took service with Charles' son, Philip II of Spain.

Vesalius is considered a founder of the excellence of Italian universities in anatomy in the sixteenth and seventeenth centuries as his dissections of the human body helped to correct misconceptions dating from ancient times. In 1564, he left for a trip to the Holy Land but died on 15 October 1564 on the Greek island of Zakynthos during the journey home.

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__** William Harvey **__ (1 April 1578 – 3 June 1657) William Harvey (1 April, 1578 - 3 June, 1657) was born in Folkestone, Kent. His father was a merchant. Harvey was educated at King's College, Canterbury and then at Cambridge University. He then studied medicine at the University of Padua in Italy, where the scientist and surgeon Hieronymus Fabricius tutored him.

Fabricius, who was fascinated by anatomy, recognised that the veins in the human body had one-way valves, but was puzzled as to their function. It was Harvey who took the foundation of Fabricius's teaching, and went on to solve the riddle of what part the valves played in the circulation of blood through the body.

On his return from Italy in 1602, Harvey established himself as a physician. His career was helped by his marriage to Elizabeth Browne, daughter of Elizabeth I's physician, in 1604. In 1607, he became a fellow of the Royal College of Physicians and, in 1609, was appointed physician to St Bartholomew's Hospital. In 1618, he became physician to Elizabeth's successor James I and to James' son Charles when he became king. Both James and Charles took a close interest in and encouraged Harvey's research.  Harvey's great contribution to medicine was his revolutionary discovery of the circulation of blood. His many experimental dissections and vivisections convinced Harvey that Galen's ideas about blood movement must be wrong, particularly the concepts that blood was formed in the liver and absorbed by the body, and that blood flowed through the septum (dividing wall) ofthe heart. Harvey first studied the heartbeat, establishing the existence ofthe // pulmonary // (heart-lung-heart) circulation and noting the one-way flow of blood. When he also comprehended how much blood was pumped by the heart, he realized there must be a constant amount of blood flowing through the arteries and returning through the veins of the heart, a continuing circular flow.

Harvey's research was furthered through the dissection of animals. He first revealed his findings at the College of Physicians in 1616, and in 1628 he published his theories in a book entitled 'Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus' ('An Anatomical Study of the Motion of the Heart and of the Blood in Animals'), where he explained how the heart propelled the blood in a circular course through the body. His discovery was received with great interest in England, although it was greeted with some scepticism on the Continent.

Harvey was also the first to suggest that humans and other mammals reproduced via the fertilisation of an egg by sperm. It took a further two centuries before a mammalian egg was finally observed, but nonetheless Harvey's theory won credibility during his lifetime. Harvey retained a close relationship with the royal family through the English Civil War and witnessed the Battle of Edgehill. Thanks to Charles I he was, for a short time, warden of Merton College, Oxford (1645 - 1646). He died on 3 June 1657.  Adapted from: [] and []

__** Zacharias Janssen **__ (c. 1580 - c. 1638) Zacharias Janssen, a Dutch optician was born in The Hague, Netherlands. His father, Hans, was a lens grinder based in Middelburg, the flourishing capital of Zeeland. Hans died four years after his son's birth, and Zacharias's mother taught her son the skills necessary for managing the family business. Janssen married in 1610, and his son Johannes Sachariassen was born the next year.

It is generally believed that Janssen built the first compound microscope around 1595. Janssen's first microscopes had a maximum magnification of only 9X, with images being somewhat blurry. Though not very useful as a scientific tool, knowledge of the principles involved spread quickly and within a few years instrument makers throughout Europe were producing improved devices.  Janssen's role in the invention of the telescope is more controversial. In early October 1608 Hans Lippershay (c.1570-1619) filed a patent claim for the telescope. Shortly thereafter Janssen testified before the Committee of Councillors of Zeeland that he knew the art of making such glasses. A third claimant was Jacob Adriaenszoon of Alkmaar, known as Jacob Metius, who after learning of Lippershay's claim advanced his own. No patent was granted since it was determined the technology was too readily available and easily copied.

On April 22, 1613, Janssen was fined for counterfeiting copper coins. He moved to Arnemuiden, where he expanded his operation to include gold and silver coins. After being apprehended in 1618 he escaped to Middelburg to avoid a death sentence. Financial difficulties followed, leading to bankruptcy in 1628 and the subsequent sale of property to settle his debts. He died sometime before 1638.  Adapted from: []

__** Antonie Van Leeuwenhoek **__ (October 24, 1632 - August 26, 1723)

Antonie van Leeuwenhoek was born in Delft on 24 October 1632. In 1648, van Leeuwenhoek was apprenticed to a textile merchant, which is where he probably first encountered magnifying glasses, which were used in the textile trade to count thread densities for quality control purposes. Aged 20, he returned to Delft and set himself up as a linen-draper. He prospered and was appointed chamberlain to the sheriffs of Delft in 1660, and becoming a surveyor nine years later. In 1668, van Leeuwenhoek paid his first and only visit to London, where he probably saw a copy of Robert Hooke's 'Micrographia' (1665) which included pictures of textiles that would have been of interest to him. In 1673, he reported his first observations - bee mouthparts and stings, a human louse and a fungus - to the Royal Society. He was elected a member of the society in 1680 and continued his association for the rest of his life by correspondence.

In 1676, van Leeuwenhoek observed water closely and was surprised to see tiny organisms - the first bacteria observed by man. His letter announcing this discovery caused widespread doubt at the Royal Society but Robert Hooke later repeated the experiment and was able to confirm his discoveries.

As well as being the father of microbiology, van Leeuwenhoek laid the foundations of plant anatomy and became an expert on animal reproduction. He discovered blood cells and microscopic nematodes, and studied the structure of wood and crystals. He also made over 500 microscopes to view specific objects.

He also discovered sperm, which he considered one of the most important discoveries of his career, and described the spermatozoa from molluscs, fish, amphibians, birds and mammals, coming to the novel conclusion that fertilisation occurred when the spermatozoa penetrated the egg.

Van Leeuwenhoek died on 30 August 1723.  Adapted from: []

Major Discoveries and Achievements //Antiqua Medicina: Medicine before the Renaissance// Discovery of Basic Anatomy
The discovery of basic anatomy was discovered by ** Galen of Pergamum **, a prominent Roman physician and philosopher of Greek origin, and probably the most accomplished medical researcher of the Roman period. His theories dominated and influenced Western medical science for well over a millennium, even though his account of medical anatomy was based largely on monkeys and pigs ("the animal most similar to man" said Galen) rather than humans, since human dissection was not permitted in his time. In addition, these animal dissections were conducted by a barber-surgeon whose work was directed by Galen.

<span style="color: #000000; font-family: Arial,sans-serif;">In this study of comparative anatomy, Galen assumed that the anatomy of monkeys and pigs were basically the same as that of humans. Because his knowledge was derived for the most part from animal (principally the Barbary ape), rather than human, dissection, Galen made many <span class="apple-style-span" style="font-family: Arial,sans-serif;">** mistakes ** <span style="color: #000000; font-family: Arial,sans-serif;">, especially concerning the internal organs. For example, he incorrectly assumed that the // rete mirabile //<span style="color: #000000; font-family: Arial,sans-serif;">, a plexus of blood vessels at the base of the brain in ungulate animals, was also present in humans. In spite of Galen’s mistakes and misconceptions, his writings reveal an <span class="apple-style-span" style="font-family: Arial,sans-serif;">** astonishing wealth of accurate detail ** <span style="color: #000000; font-family: Arial,sans-serif;">.

Galen’s instincts lead him to realize the fundamental importance of organs and their effective roles. For example, he understood that the urinary bladder did not produce urine but that this came from the ureter (demonstrated by joining the ureters together and observing the subsequent swelling of the kidneys). Another instance would be the way Galen studied the function of nerves by cutting them, and thereby showed paralysis of the shoulder muscles after division of nerves in the neck and of voice loss after interruption of the recurrent laryngeal nerve. Furthermore, Galen emphasized other therapeutic methods, such as blood-letting (withdrawal of often considerable quantities of blood from a patient to cure or prevent illness and disease). He also introduced the Methodist concept of the pores, but this was distorted into an invitation not to wash oneself because water could obstruct the pores.

=== Yet, whatever Galen discovered had no experimental basis, but, because it fitted well with Christian doctrine, it then became almost a dogma and was still considered to be valid in the 16th century at the times of the great Vesal. Galen, for all his mistakes, remained an unchallenged authority in his lifetime, and his work established a legacy that continued for over a thousand years, up till the printed description and illustrations of human dissections by Andreas Vesalius in 1543. ===

=//<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 80%; font-weight: normal;">Medicine during the Renaissance //=

=<span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">Discovery of Modern Human Anatomy = = Andreas Vesalius was a Flemish-born anatomist whose dissections of the human body helped to correct misconceptions dating from the Middle Ages. =

Back then, surgery and anatomy were considered of little importance in comparison to the other branches of medicine. However, Andreas Vesalius believed that surgery had to be grounded in anatomy. Previously, these topics had been taught primarily from reading classic texts, mainly Galen, and no attempt was made to actually check Galen's claims; these were considered unassailable. Vesalius, on the other hand, carried out dissection as the primary teaching tool, handling the actual work himself while his students clustered around the table. Hands-on direct observation was considered the only reliable source, a huge break with medieval practices.

Andreas Vesalius managed to overturn and prove wrong many of Galen’s claims, and in addition discover more about human anatomy himself. In 1538 he also published a letter on bloodletting, a popular treatment for a variety of illnesses through bleeding. There was debate about where in the body the blood should be taken from. Vesalius' letter was supported by his knowledge of the blood system and he showed clearly how anatomical dissection could be used to test speculation, and underlined the importance of understanding the structure of the body in medicine.

In 1539, Vesalius’ supply of dissection material increased when a Paduan judge became interested in Vesalius' work, and made bodies of executed criminals available to him. Vesalius was now able make repeated and comparative dissections of humans. This was in marked contrast to Galen, the standard authority on anatomy who, for religious reasons, had been restricted to animals, mainly apes. Vesalius realized that Galen's and his own observations differed, and that humans do not share the same anatomy as apes.

One famous example of Vesalius disproving of Galen’s work includes the fact where Galen assumed arteries carried the purest blood to higher organs such as the brain and lungs from the left ventricle of the heart, while veins carried blood to the lesser organs such as the stomach from the right ventricle. In order that this theory could be correct some sort of holes were needed to interconnect the ventricles, and so in the spirit of Galen's time, he claimed to have found them, adjusting the facts to suit his theory. So paramount was the authority of Galen that for the next 1400 years, a succession of anatomists claimed to find these holes until finally Vesalius declared he could not find them. However, while Vesalius dared to admit he could not find these holes, he did not dream of disputing Galen on the distribution of blood, and so imagined it distilled through the unbroken partition between the ventricles.

In 1543 Vesalius published his revolutionary book ** De humani corporis fabrica ** **// ( //**** On the Structure of the Human Body) **, whereby there were seven volumes in total on the structure of the human body. All were illustrated in detail by artists using Vesalius's own drawings. The book depicted and described several organs such as the thalamus for the first time. Never before had illustrations of this quality been seen in a medical book. It was the most accurate and detailed anatomical text ever to have been produced.

The book was a major breakthrough in medical history for a number of reasons. It developed the use of technical drawings and disproved theories that had been in place in Europe for many hundreds of years. Despite the clarity of his work, argument and presentation however, many people chose to dispute his theories at the time: convinced that the works of Galen were correct.

= Discovery of Blood Circulation = <span style="color: #000000; font-family: Arial,sans-serif;">Although many scientists had already more or less hypothesized about the human circulatory system, it was only up till British physician ** William Harvey **<span style="color: #000000; font-family: Arial,sans-serif;"> stepped in and did his research that people started to question Galen’s work. He was the first to describe correctly and in exact detail the systemic circulation and properties of blood being pumped around the body by the heart.

William Harvey focused much of his research on the mechanics of blood flow in the human body. Most physicians of the time felt that the lungs were responsible for moving the blood around throughout the body. Harvey questioned these beliefs and his questions directed his life-long scientific investigations.

William Harvey's experiments involved both direct dissection and physiological experiments on animals. His observations of dissected hearts showed that the valves in the heart allowed blood to flow in only one direction. 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 arteries and veins, not perforations. When William 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. Removal of the blood from human cadavers showed that the heart could hold roughly two ounces of blood. By calculating the number of heartbeats in a day and multiplying this by two ounces, he showed that the amount of blood pump far exceeded the amount that the body could possibly make. He based this figure on how much food and liquids a person could consume.

To Harvey, this showed that the teaching by Galen that the blood was being consumed by the organs of the body was false. Blood had to be flowing through a 'closed circuit' instead. Even though he lacked a microscope, Harvey theorized that the arteries and veins were connected to each other by capillaries, which would later be discovered by Marcello Malpighi some years after Harvey's death. Like all good research, Harvey's work raised more questions than it answered. For example, if blood was not consumed by organs, how did different parts of the body obtain nourishment? If the liver did not make blood from food, where did blood originate? These questions, and others like them, directed the research of many investigations for many years to come. Yet medical practice did not change right away. Even though the mechanics of blood flow were understood now, the understanding of the causes of many diseases was still bathed in the mystery of spirits. In fact, the practices of bleeding, lancing, and leeching increased in the years following Harvey's work. On the positive side, medicine did make some advances, for it was during the seventeenth century that administering medicine through intravenous injections came into practice.

William Harvey's classic work became the foundation for all modern research on the heart and cardiovascular medicine. It has been said that Harvey's proof "of the continuous circulation of the blood within a contained system was the seventeenth century's most significant achievement in physiology and medicine." Further, his work is considered to be one of the most important contributions in the history of medicine. Without the understanding of the circulatory system made possible by Harvey's pioneering work, the medical miracles that we think are commonplace would be impossible.

= Invention and Improvement of Microscope, Establishment of Microbiology =
 * Sacharias Janssen ** is generally believed to be the first investigator to invent the compound microscope. Though rudimentary when compared with modern models, the Janssen microscope was an important advance from contemporary use of a single lens for magnification purposes. With further developments in microscopy, a formerly unknown and invisible world was to become readily apparent. His invention paved the way for more future medical discoveries, and by the end of the seventeenth century, Robert Hooke had employed his version of the compound microscope to observe organisms, such as fossils, diatoms, and even cells, and Marcello Malpighi had discovered capillaries.

<span style="color: #000000; font-family: Arial,sans-serif;">However, because of the various technical difficulties in building these microscopes, early compound microscopes were not practical for magnifying objects more than twenty or thirty times its natural size. It was only up till ** Antonie van Leeuwenhoek **<span style="color: #000000; font-family: Arial,sans-serif;">’s research and improvement on the existing microscope were the entire world of microscopic life opened up to the awareness of scientists.

Leeuwenhoek's skill at grinding lenses, together with his naturally acute eyesight and great care in adjusting the lighting where he worked, enabled him to build microscopes that magnified over 200 times, with clearer and brighter images than any of his colleagues could achieve. What further distinguished him was his curiosity to observe almost anything that could be placed under his lenses, and his care in describing what he saw. Although he himself could not draw well, he hired an illustrator to prepare drawings of the things he saw, to accompany his written descriptions. Most of his descriptions of microorganisms are instantly recognizable.

During his lifetime Van Leeuwenhoek ground over 500 optical lenses. He also created over 400 different types of microscopes, only nine of which still exist today. His microscopes were made of silver or copper metal frames holding hand-ground lenses. Those that have survived the years are able to magnify up to 275 times. It is suspected, though, that Van Leeuwenhoek possessed some microscopes that could magnify up to 500 times. Although he has been widely regarded as a dilettante or amateur, his scientific research was of remarkably high quality.

Using his handcrafted microscopes he was the first to observe and describe single celled organisms, which he originally referred to as // animalcules //, and which we now refer to as microorganisms. <span style="color: #000000; font-family: Arial,sans-serif;"> Other discoveries include the observations of bacteria, spermatozoa, and striped muscle. He also observed the red blood cells in his detailed study of capillary circulation. The invention of the microscope refuted the doctrine of spontaneous generation, and his observations helped lay the foundations for the sciences of bacteriology and protozoology.

** Importance of these Discoveries **

= Discovery of Basic Anatomy = The discovery of basic anatomy in the first few centuries of earliest recorded time by Galen, the most famous doctor of the Roman Empire, was a highly significant achievement, being one of the pioneering beginnings of medicinal study. It was significant to the extent of its effects (Galen’s formulated views on the basic anatomy of the human body) dominating European medicine for one and a half millenniums, all the way til the 1600s, around the time where the Scientific Revolution first began to emerge from the end of the Renaissance Age.

Galen’s ‘embarking on extensive travels’ for the sake of ‘broadening his medical knowledge with studies’, in an age where transport was often arduous and inconvenient, represents that academic research was especially important to him, taking into account the lengths Galen was willing to go to for the sake of academic betterment in an era where knowledge was collected merely as an abstract whim for the sake of acquiring wisdom that served only a theoretical purpose, rather than for producing practical solutions and improvements on day-to-day problems, which was how Galen’s discoveries eventually contributed to the medical field (eg. Research on the urinary bladder and the function of the nervous system, research on the uses of therapeutic plants). This mindset of prioritizing the progress of academics and research could have been the trend-setting mindset that subsequent generations of scientists, inspired by Galen’s trailblazing work, adopted when coming up with their own contributions which were similarly instrumental in promoting further scientific progress.

Galen’s precise methods of observing the corresponding effects of different scenarios (carried out for the sake of research) were also significant in their demonstration of a very modern way of scientific thinking- logical deductions and conclusions based on careful observation and phenomena. These methods were especially advanced taking into account the very primal era in which they were used. For example, way Galen studied the function of nerves by cutting them, and thereby showed paralysis of the shoulder muscles after division of nerves in the neck and of voice loss after interruption of the recurrent laryngeal nerve.

The repercussions of Galen’s work were highly significant. Galen’s discoveries revolved around his central belief in a divine purpose for all living things, even for concepts as scientific as the structure and functions of the human anatomy. This underlying purpose which had no experimental basis but boded well with Christian doctrine was highly approved by the newly ascendant Christian church, which appointed his teachings as the ultimate medical authority. This was significant in that Galen’s work proved to be a mixed blessing; although it contributed greatly to society in that it was a pioneering feet, promoting scientific research and forming the basis of medicine for 1500 years, it simultaneously prevented the development of any further scientific research that contradicted Galen’s theories, many of which were false, and thus slowed down the development of medicine by one and a half millenniums. The Church’s fervent approval of Galen’s work discouraged further scientific research as any contradictory data would be considered heresy. In conclusion, while Galen’s remaining an unchallenged authority in his lifetime (and in the subsequent period of time til the 1600s) can have been said to have been a pioneering feat, it brought about great delays in the progress of science.

= Discovery of Modern Human Anatomy = Andreas Vesalius’ belief of surgery being grounded in anatomy and the importance of understanding the structure of the body was significant in that it contributed in no small way to his being provided with the unprecedented opportunity to access human bodies for dissections which led him to producing the groundbreaking results that overthrew Galen’s flawed theories (formulated based on apes, which had differing anatomy from humans) that had remained the unchallenged authority in medicine for a solid 1500 years. This meant that Andreas Vesalius had single-handedly brought the world away from a system of misconception towards a more accurate future in medicine and science, which was a significant achievement taking into account the remarkably long time that Galen’s theories had remained unchallenged.

Andreas Vesalius also played an integral role in continuing the fundamentals that Galen had performed his work upon, by further transforming anatomy into a subject that relied on hard proof- observations taken directly from his experiments in human dissection. This not only helped to correct misconceptions dating from ancient times, but also ensured the continuity of the scientific way of thinking that provides a degree of certainty in our current investigations that previously did not exist. His daring to contradict an unchallenged authority in an era where disputing the norm was easily regarded as heresy at the time, a crime that brought with it terrible punishment, was similarly significant in that it brought about his being able to break away from the barrier Galen’s work had set up (that had limited all scientific investigations that contradicted Galen’s aforemenoned theories) – which not only represented tremendous courage, but also represented the rebirth of scientific progress after a long, limiting hiatus. This daring took the form of technical drawings (eg. in his book De Humani Corporis Fabrica (On the Fabric of the Human Body), which was the most accurate and detailed anatomical text to have been ever produced at the time) and disproving theories that had been in place in Europe for many hundreds of years.

= Discovery of Blood Circulation = William Harvey, the first to describe correctly and in exact detail the systemic circulation and properties of blood being pumped around the body by the heart, carried out his lifelong investigations directed by his constant questioning of his beliefs. For example, if blood was not consumed by organs, how did different parts of the body obtain nourishment? If the liver did not make blood from food, where did blood originate? By continually searching for the answers to endless questions rather than blindly accepting facts as they came, he, as well, as able to make amazing scientific discovery.

William Harvey was a fervent believer in using evidence to back up his claims and authenticate his discoveries. For example, in his investigations with blood, he used mathematical data to prove that the blood was not being consumed. By estimating the volume of blood the heart could hold and multiplying this by the average number of daily heartbeats he proved that the amount of blood flowing through the body was more than any 1 organ was producing. This method of thinking via logical deduction and conclusion was also testimony to the fact that scientists not only built on each other’s discoveries, but also their methodology and ways of processing thought. Harvey’s constant testing of his work resulted in his contributing the most significant achievement in the field of physiology and medicine, which promoted an unprecedented understanding in the field of physiology and medicine and provided the foundation for the medical methods of healing that save lives today.

= Invention and Improvement of Microscope, Establishment of Microbiology = The groundbreaking contributions of Leeuwenhoek, who illuminated the existence of a formerly unknown and invisible world, were especially significant because all previous medical breakthroughs had been based on tangible things that were visible to the naked eye, whereas Leeuwenhoek’s invention of the microscope alerted people to the existence of a whole entire species they previously had had no inkling about, which were a significant representation of progress in science- from discovering new information by building on existing knowledge about the world to discovering entirely new worlds with absolutely no prior knowledge of their existence. This could not have been done, either, without his detailed care in describing his findings, fuelled by his passion and curiosity to ‘observe almost anything that could be placed under his lenses’, which was significant in it’s paving the way for the development of the scientific drawing.

The invention of the microscope not only helped lay the foundations for the sciences of bacteriology and protozoology that in turn laid the foundations for many medical breakthroughs in modern science today, but also served to refute the doctrine of spontaneous generation that had been the agreed norm up til that point. This was just one of the many groundbreaking fundamental changes that set the stage for the onset of modern science and that made the period between the death of Copernicus and the work of Newton, who avidly continued the work of Copernicus with increased zeal, a revolution of scientific progress.

**<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 150%;">Bibliography ** · Tel Asiado. (2008, August 4). Anatomist Andreas Vesalius. Retrieved February 5, 2010, from // http://greatthinkers.suite101.com/article.cfm/anatomist_andreas_vesalius // · // BBC //. (n.d.). Retrieved February 5, 2010,from // http://www.bbc.co.uk/history/historic_figures/vesalius_andreas.shtml // · // FAQ.org //. (n.d.). February 5, 2010, from // http://www.faqs.org/health/bios/62/William-Harvey.html // · // Sacklunch.net. // <span style="color: #000000; font-family: Arial,sans-serif;">(n.d.). Retrieved February 5, 2010,from // http://www.sacklunch.net/biography/H/WilliamHarvey.html // · // BBC //. <span style="color: #000000; font-family: Arial,sans-serif;">(n.d.). Retrieved February 5, 2010,from // http://www.bbc.co.uk/history/historic_figures/harvey_william.shtml // · // BBC //. <span style="color: #000000; font-family: Arial,sans-serif;">(n.d.). Retrieved February 5, 2010,from // http://www.bbc.co.uk/history/historic_figures/galen.shtml // · <span style="color: #000000; font-family: Arial,sans-serif;">World of Scientific Discovery on Galen. // Bookrags //. <span style="color: #000000; font-family: Arial,sans-serif;">(n.d.). Retrieved February 5, 2010,from // http://www.bookrags.com/biography/galen-wsd/ // · // FAQ.org //. <span style="color: #000000; font-family: Arial,sans-serif;">(n.d.). Retrieved February 5, 2010,from // http://www.faqs.org/health/bios/38/Galen.html // · <span style="color: #000000; font-family: Arial,sans-serif;">Sacharias Jansen. // Bookrags //. <span style="color: #000000; font-family: Arial,sans-serif;">(n.d.). Retrieved February 5, 2010, from // http://www.bookrags.com/research/sacharias-jansen-scit-0312345/ // · // BBC //. (n.d.). Retrieved February 5, 2010, from // http://www.bbc.co.uk/history/historic_figures/van_leeuwenhoek_antonie.shtml // · <span style="color: #000000; font-family: Arial,sans-serif;">Simon & Schuster, “Scientific Revolution- WHAT WERE THE NATURE AND CHARACTERISTICS OF THE SCIENTIFIC REVOLUTION IN THE 17TH CENTURY?”, HS-102 Readings (online), Retrieved February 14, 2010, from // http://74.125.153.132/search?q=cache:jfO7HTGB3EYJ:www.sunysuffolk.edu/~westn/science.html+major+medicine+developments%2Bscientific+revolution&cd=3&hl=en&ct=clnk&gl=sg // · <span style="color: #000000; font-family: Arial,sans-serif;">Brannon, Heather, “The History of Smallpox- The Rise and Fall of a Disease”, About.com: Dermatology (online), Retrieved February 14, 2010, from // http://dermatology.about.com/cs/smallpox/a/smallpoxhx.htm // · <span style="color: #000000; font-family: Arial,sans-serif;">St Richard’s Catholic College, “Medicine through Time (The Renaissance and Scientific Revolution)”, History GCSE Revision (online), Retrieved February 14, 2010, from, // http://www.st-richards.e-sussex.sch.uk/humanities_site/page4.html // · <span style="color: #000000; font-family: Arial,sans-serif;">University of Virginia, “Galen”, History Collections. Retrieved February 16, 2010, from, // http://www.hsl.virginia.edu/historical/artifacts/antiqua/galen.cfm // · Florida State University. “Zacharias Janssen”. Retrieved February 16, 2010, from, // http://micro.magnet.fsu.edu/optics/timeline/people/janssen.html //
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