Advances in Dissection, Laboratory Medicine, Germ Theory and Medical Implements

This essay will discuss the movement of medical care from the ‘patient knows best’ approach to the ‘Doctor knows best’ approach. Advances in dissection, laboratory medicine, germ theory, and medical implements, combined with contributions from many individuals, lead to this shift in healthcare away from being the domain of the patient, towards becoming the domain of the doctor.

The ‘patient knows best’ approach is a system of medicine where the power dynamic works in the patients’ favor, meaning they are more in control of their own care than doctors are, and is influenced by many factors.

The majority of the general public could not afford to see a university-trained doctor and therefore had to resort to visiting unlicensed practitioners such as barber surgeons, apothecaries, or quacks. Patients were looking for quick fixes and wanted to feel in control of their medical care, a doctor’s consultation was expensive and often inconclusive, whereas a quack would offer a remedy without much investigation for a comparatively reasonable price. Most of the public had not developed a sense of skepticism for the quacks’ outlandish claims, also these individuals were often extremely charming, charismatic, and knew how to employ advertising techniques to their full advantage, therefore the patients took whatever pill, balm, or potion they were offering. This process supported the ‘patient knows best’ system because it put all the power in the patient’s hands, they chose the medication that they felt was best for their condition and were not questioned on it, the quack took their money and left.

During the 18th and 19th Century, there were very few university-trained doctors practicing and their patients were mainly from the aristocratic upper class. This disparity in status and quantity contributed to a patient-dominated healthcare system because doctors had to compete for their limited number of patients, therefore, pleasing the patient was paramount. A symptom-based model of illness arose in response to this. Doctors found treating the patient’s individual symptoms, based on their specific needs and experiences through being attentive, was positively received by the patient, therefore it remained the dominant model of care throughout the period. This symptom-based model was reinforced due to the ineffectiveness of available tests and treatments. Medical decisions had to be made based on the self-reporting of symptoms in the sick person’s own words. The patient was the only source of information on their illness and recovery, therefore they had to be at the forefront of the approach to medical care.

Dissection has remained a critical component of medical education for centuries. While its most basic purpose, to learn about the structure and functions of the human body, has not changed, attitudes of medical professionals, educators, and the general public have shifted and evolved as societal views have changed.

During the 3rd Century BC Greek physicians, Herophilus and Erasistratus performed dissections in the Greek School of Medicine in Alexandria, Egypt. However, by the 2nd Century AD, the practice of dissection had become such a cultural taboo that it had fallen out of favor in both Greece and Rome, leading physician Galen to resort to dissecting animals in an effort to understand the human body. During this period it was widely accepted that monkeys’ and humans’ inner workings were extremely similar, therefore Galen practiced dissections on monkeys, specifically Barbary and rhesus macaques. This lead to many errors in Galen’s findings, and, given that there was no way to refute them, his assumptions persisted as medical knowledge for over 1400 years.

By the Middle Ages, the material world and physical body were considered by theologians and philosophers to be inconsequential compared to eternity, thus human anatomy was not a focus of exhaustive study. Furthermore, dissection was considered to be a desecration of the body and therefore was prohibited. However, by the 15th and 16th centuries, a scientific revolution had begun and some French and Italian university professors started using cadavers to emphasize lectures from ancient Greek and Latin texts. A shift towards scientific research and observation led to the return of human dissection, which laid the foundations for the modern-day practice of medicine where the focus is on the extensive evidence-based knowledge of doctors. The Renaissance was a time of major change and brought about a transition from the theology-focused Middle ages towards a scientific method relying on experimentation, practical testing, and experience, with renewed interest in the human body.

The dissection of human cadavers continued to be prohibited in England until the 16th century, after which a very limited number of the corpses of hanged criminals were permitted to be used for dissection. However, by the 17th century, the demand for cadavers had risen dramatically due to the availability of anatomy texts from Italy and France. The pressure from anatomists for more cadavers to study led to the passing of the Murder Act in 1752, which legalized the dissection of all executed murderers, providing medical schools with an adequate supply of cadavers and also acting as a deterrent for the crime of murder. The government also increased the number of crimes that were punishable by hanging, however, this still proved insufficient due to the expansion in medical training and anatomical study throughout the 18th century, and to make up the numbers the practice of illegally exhuming cadavers from graveyards arose. The men who carried this practice out became known as ‘resurrectionists’ and sold the bodies to medical schools. It is likely that body snatchers provided the majority of cadavers to medical schools in the 18th and early 19th centuries and as part of an attempt to control the trade in corpses the 1832 Anatomy Act in Britain was introduced. At first unclaimed bodies of the poor and ill were allowed to be taken for medical schools, then later the family’s permission was required before a body could be taken. The act was amended and refined as the need for cadavers in medical education and research became widely recognized. Today consent is a vital part of cadaveric dissection, gaining permission from the patient or their family reinforces the public’s trust in medical professionals.

Dissection, and its clear benefit to scientific research, helped strengthen the rise of a professional monopoly. Doctors had the tools to scientifically prove their theories and ideas and they began to consistently have more knowledge than their patients. This caused a shift in power between patient and doctor in favor of the doctor, leading to the ‘Doctor knows best’ approach is dominant.

Dissection is still practiced in medical schools across the world, however, it is becoming increasingly common for computer models to be used as teaching tools for anatomy. Dissection most often occurs as part of a post-mortem or autopsy or as part of a forensic investigation.

“Laboratory medicine works to diagnose disease, evaluate the effectiveness of treatment, and to research the causes and cures of disease.”

This is achieved through the study of tissue, blood, or other bodily fluid specimens at the molecular level outside of the body and through specialized imaging such as x-rays and MRI. Some fields of laboratory medicine include microbiology, hematology, pathology, and immunology.

Fields such as pathology could only develop as science developed. Ancient Greek physicians performed dissections and autopsies on human cadavers for 30 to 40 years, however when human dissection was forbidden scientific progress was hindered, leading to the widespread subscription to the humoral theory of medicine. During the Enlightenment of the 18th century, the theory of the four senses of humor was disproved as medical education developed. The legalization of human dissection allowed the study of pathology to develop quickly as autopsies were more frequently performed and physicians then began to consider that pathology could inform diagnosis.

The introduction of laboratory medicine to the diagnostic process was not simple, however. By the late 1800s use of laboratory medicine was limited, the majority of specimens received by pathologists were the byproducts of surgery, such as amputated limbs, drained fluids, and excised tumors. In the case of a tumor, pathologists were expected to provide an account of the appearance, macroscopic and, sometimes, microscopic.

Usually, the surgeon was satisfied with their evaluation of the tissue they had excised and expected the pathologist to elaborate on the diagnosis they had already decided on. In this way, the pathologist acted as a check of clinical diagnosis, usually confirming it, but sometimes correcting the surgeon’s conclusion. Disagreements over-diagnosis lead to some tension over each clinician's authority, and, while many surgeons were happy to defer to the pathologist, others were not.

As more and more correct medical decisions and diagnoses were influenced by the use of laboratory medicine, such as pathology, it became clear that it was an invaluable tool in medicine. Furthermore, it provided clear proof of scientific findings and widened the disparity in knowledge between medical professionals and the general public. This shift in power directly influenced the shift from a ‘patient knows best’ to a ‘Doctor knows best’ approach to medicine.

Germ Theory states that microorganisms or pathogens are known as ‘germs’, cause disease by invading a host and then growing and reproducing within them. This theory developed in the 1800s gradually gaining acceptance and eventually superseding the existing theories of miasma and spontaneous generation. This radically changed the practice of medicine and remains the guiding theory of medical science.

The physical existence of germs was proven in 1677, over two centuries before the development of Germ Theory, by Antoni van Leeuwenhoek through his simply constructed microscope. He called the tiny organisms he found in a drop of water ‘animalcules’, however, he made no connection with disease, instead surmising they were an effect of disease, which fitted with the then-popular theory of spontaneous generation.

Years of development and research by Ignaz Semmelweis, Joseph Lister, and John Snow would retrospectively contribute to the acceptance of Germ Theory, however, it was the research of Louis Pasteur in the 1860s and then Robert Koch that provided the scientific proof which solidified the theory.

Louis Pasteur demonstrated the existence of germs through a heavily publicized experiment: he developed a vaccine for anthrax by reducing the virulence of the bacterium by exposing it to air and vaccinating one group of farm animals while leaving another group unprotected. A month later all of the animals were exposed to a lethal dose of anthrax. Two days later Pasteur and the waiting press found the vaccinated animal alive and well while the unprotected group was all dead. The publicity meant that the public and scientific community could no longer deny the validity of germ theory.

The development of medical knowledge and approach to healthcare into what we see today has been greatly influenced by the contributions of many individuals as in the case of Pasteur's anthrax experiment.

One such individual is John Hunter, a surgeon, often credited as the founder of pathological anatomy in England. He was an early advocate of scientific investigation and experimentation, even self-experimentation. He conducted and encouraged his students to conduct, studies and experiments in comparative aspects of biology, anatomy, physiology, and pathology.

He not only made important scientific contributions to the field of surgery but also achieved for surgery the dignity of a scientific profession. This was achieved by basing the practice of surgery on biological principles and a vast body of knowledge gained through extensive scientific experimentation.

As a teacher, Hunter inspired a generation of physicians to base their practice on scientific evidence, rather than on belief in unproven but popular theories. In his lectures, Hunter stressed the relationship between structure and function in all kinds of living creatures. He believed that surgeons should understand how the body compensated for, and adapted to, damage due to injury, disease, or environmental changes. He encouraged students such as Edward Jenner to carry out experimental research and to apply the knowledge gained to the treatment of patients. Hunter’s thorough teaching of the scientific process leads Jenner to go on to develop a vaccine for smallpox, an extremely contagious and deadly virus, one of the most important medical breakthroughs of all time. During Jenner’s time as a practicing physician epidemics of smallpox raged across the world. In order to combat the disease Jenner, like many others, practiced variolation, the process of exposing healthy patients to material from a smallpox victim hoping that contracting a mild dose would lead to immunity. While this method was sometimes effective, it could result in full infection and even death.

Folklore of the time suggested that milkmaids who contracted cowpox, a mild disease in humans, never contracted smallpox. After studying this matter, Jenner conducted an experiment to prove his theory that cowpox could produce immunity to smallpox. In 1796, he infected an eight-year-old boy named James Phipps by inserting pus from a cowpox pustule into an incision on the boy’s arm. Six weeks later the boy was variolated with smallpox and suffered no ill effects, proving Phipps was now immune to smallpox.

It took many years for Jenner’s findings to be widely accepted and he conducted many more experiments, vaccinating several other children including his own eleven-month-old son. Once the efficacy of his vaccination was accepted and its obvious benefits were realized Jenner was praised all over the world and vaccination became commonplace.

In 1979, after a widespread vaccination campaign, the World Health Organisation declared smallpox the first infectious disease in history to be eradicated. Without Jenner and his scientific contributions, this would not have been possible.

Medicine has been greatly advanced by the invention of the vaccine, and also the development of many other medical implements and machines. For example, discoveries in areas like germ theory and pathology would not have been possible without the microscope.

For over 2000 years humans have known that glass bends light. In the first century AD Romans invented and began to experiment with lenses, discovering their ability to magnify objects. But it wasn't until the late 17th century that the first real microscope was made by a Dutch scientist, Antony Van Leeuwenhoek. His microscope consisted of a single convex glass lens which was attached to a metal holder and used screws to focus. This new microscope was able to do things never observed before such as bacteria, yeast, and blood cells.

Leeuwenhoek made pioneering observations of freshwater microorganisms using his simple microscope and in 1674 launched the study of microbiology. His microscope design remained popular until the 1850s, even being used by Robert Brown in 1827, a botanist who observed the universal presence of the cell nucleus.

Over many years of research and development, countless people, including influential royalty, paid tribute to early microscopists, but by the medical world, however, including renowned anatomist John Hunter, they were largely ignored or even ridiculed. More than 200 years passed before the true value of microscopes was appreciated by clinicians and laboratory scientists. Today the microscope is an invaluable laboratory tool in hospitals and medical schools around the world.

It is clear that a major component in the shift from the ‘patient knows best’ approach to the ‘Doctor knows best’ approach to medical care is the acquisition of scientific, evidence-based knowledge and its impact on the power dynamic between doctor and patient. Society’s overall view of medicine began to shift in the 18th and 19th centuries as the need for scientific research in order to produce accurate and effective testing and treatments became clear. There was a move away from unspecific, personal, patient-focused traditional medicine toward the standardized, evidence-based professionalization of medicine we see today.

The advances in dissection had a profound impact on the prevailing approach to medicine. These advances were made possible by a governmental intervention which allowed more dissections and more research to be performed. Without the Murder Act of 1752 and the later 1832 Anatomy Act, doctors would not have been able to provide clear evidence for theories or prove the efficacy or inadequacy of treatments. These votes of confidence from the government showed people that dissection was useful and necessary for the advancement of medical knowledge. Patients recognizing the increasing disparity in knowledge between themselves and doctors was a crucial component in the shift from a patient lead approach because it allowed professional licensed doctors to monopolize the healthcare system. Patients saw that a quack or apothecary had no scientific reasoning behind, or evidence for, their treatments and therefore turned to trusted doctors.

Similarly, laboratory medicine provided clear and incontestable scientific proof of doctors’ findings, or in some cases highlighted incorrect treatment choices or misdiagnoses. This meant that over time laboratory medicine became the essential component of medical care it is today. Fields of Laboratory medicine like pathology, radiology, and immunology provide doctors with evidence that proves to patients they are not only being treated effectively but that doctors are constantly checking they are making the best decisions for their patients. Therefore, while widening the gap in knowledge between patient and doctor, laboratory medicine also instills trust in doctors and medical professionals which allows patients to feel more comfortable in a doctor-dominated medical system.

Antony Van Leeuwenhoek’s initial development and application of the microscope provided a solid foundation for the work of scientists like Louis Pasteur and Robert Koch to conduct research that provided strong evidence for Germ Theory. In much the same way as the rise of dissection and laboratory medicine, this development led to a more doctor-dominated approach to medicine. They had more power over their patients because there was a quickly growing knowledge inequality. The advancement of germ theory meant doctors had proof that other theories about the disease, such as miasma, were untrue and therefore only their treatments worked, further reinforcing their rapidly increasing professional monopoly.