What is Pathology?

Pathology is a basic medical science that studies the causes, mechanisms, development rules, and morphological structure, functional and metabolic changes, and disease outcomes of the body during the disease.

Development of Pathology

Pathology came into being in the process of human exploration and understanding of its own disease. Its development is bound to be restricted by human's ability to recognize nature. From the Hippocrates of ancient Greece, after more than 2,000 years of development, until the middle of the 18th century, the rise of natural sciences promoted the advancement of medicine. Italian medical scientist Morgagni (1682-1771) created organ diseases based on accumulated autopsy materials. Physiology (organ pathology) marks the beginning of pathological morphology. About a century later, in the middle of the 19th century, German pathologist Virchow (1821 ~ 1902) created the first celluar pathology with the help of a microscope, which not only made pathology but also the development of medicine as a whole. Historic and landmark contribution. His doctrine continues to influence the theory and practice of modern medicine.

World famous books such as the Yellow Emperor's Canon of Internal Medicine of the Qin and Han Dynasties, Chao Yuanfang's Theories of the Sources of Diseases during the Sui and Tang Dynasties, and Song Ci's Collection of Injustices during the Southern Song Dynasty have made great contributions to the development of pathology. For more than half a century, the pioneers of modern Chinese pathology Xu Yuming, Hu Zhengxian, Liang Boqiang, Gu Jingyi, Hou Baodi, and Lin Zhengang, Qin Guangyu, Jiang Qingfen, Li Peilin, Wu Zaidong, Yang Shuzu, Yang Jian, Liu Yong, etc. have taught Chinese pathology and trained teachers And the development of pathology, painstaking efforts, hard work and outstanding achievements. Under their auspices and participation, China has compiled its own pathology textbooks and reference books with Chinese characteristics from scratch. At the same time, vigorously promote China's pathological autopsy and biopsy work and scientific research work to endemic and parasitic diseases (such as Keshan disease, Kashin-Beck disease, black fever, schistosomiasis, etc.), tumors (such as liver cancer) , Esophageal cancer, nasopharyngeal cancer, etc.) and cardiovascular diseases (such as atherosclerosis, coronary heart disease, etc.) are common and frequently-occurring. Extensive research has been carried out and fruitful results have been achieved. These achievements have played an important role not only in the current pathology teaching, scientific research and laboratory work in China, but also in the development of Chinese pathology in the future.

The development of pathology is closely related to the development of natural science, especially the development of basic science and technology. When people can only rely on the naked eye and a simple magnifying glass to observe events, they can only produce organ pathology; only after the advent of microscope and cytology, cytopathology may be born; and for more than half a century, due to the electron Microscopy technology, especially the successive establishment of a series of new methods and technologies for more than 20 years, and the rapid rise and development of emerging disciplines and their branches such as cell biology, molecular biology, environmental medicine, and modern immunology and modern genetics. Medical science has also had a profound impact on the development of pathology and brought new impetus. Since the beginning of the 21st century, ultra-structural pathology includes molecular pathology, molecular immunology, molecular genetics, etc. The establishment and promotion of pathology have not only understood the relevant diseases from the cellular and subcellular levels, but also from the molecular level, human genetic mutations and chromosomal aberrations, and studied the causes and pathogenesis of the diseases. Modern genetic pathology believes that although only a small part of human diseases have obvious genetic characteristics, in principle almost all diseases are affected by genetic factors. Modern immunopathology research has gradually elucidated the etiology, pathogenesis and nature of many diseases that have not been recognized for a long time, and found that the occurrence and development of many diseases are closely related to the body's immune status. These advances and discoveries have opened up new prospects for the prevention and treatment of many diseases.

Chinese pathology has made great progress on the solid foundation laid by senior pathologists, and has made great progress in the construction of teams and conditions through the efforts of a new generation of pathologists. China is a large country with a large population. The disease spectrum and diseases have their own characteristics. To carry out research in this area is of great significance not only for China's medical development and disease prevention, but also for the world's medicine. Facing this task, the development of Chinese pathology has full realistic conditions and broad prospects. At present, we must face reality, vigorously promote and carry out pathological autopsy work, make full use of China's abundant disease material "resources", actively develop China's human pathology, and also make full use of various ways to absorb new methods in the world New technology, meanwhile, it is necessary to develop and establish its own new methods and technologies in accordance with the actual situation in China, strengthen China's experimental pathology research, and make the development of Chinese pathology keep pace with the development of world pathology, and in some aspects Leading. This is the responsibility and task of contemporary Chinese pathologists.

History of Pathology

Pathology is a science that studies biological diseases. It is a combination of the two Greek characters Pathos and logos, translated into Chinese, which means disease and learning. Human pathology studies human diseases, and its history can be said to be a modern medical history.

Prehistoric times believed that ghosts and gods invaded the human body with tangible or intangible bodies and developed diseases. This is the first explanation of the disease. Natural medicine and witchcraft are the first two attitudes that are used by humans in the face of the mystery of disease; experience and belief are the two foundations of medical trends. In ancient times, including Mizobudamia between the two West Asian river basins, Egypt on the Nile River, China in the Yellow River Basin, and India in the Ganges River were all dominated by witchcraftreligious medicine, or monk medicine. Empirical medicine in the West is gradually influenced by the concept of the universe. The mechanism of the human body is often explained by the phenomenon of nature. The ancient Egyptians believed that the universe was originally filled with the chaotic state of "primitive water". Later, the atmospheric god "repaired" and held up the goddess of sky-Nuot, to separate the heaven and the earth, so the universe gave birth to life and all activities. Yu Yan unfolded.

In the Greek era, based on religious cues and psychotherapy, the temple medicine of the medical god Asclepios still existed, but the empirical medicine of reasonable thinking gradually rose due to the development of philosophical ideas. They no longer explained the phenomena of the universe with the power of the gods, and the physician was thus completely separated and independent by the monks. The Greek scientific philosopher Thales (639-544 BC), known as the "Father of Philosophy" and "Father of Science", believes that water is the source of all things. The influence was followed by his student Anaximenes (588-524 BC), who thought it was air, and Heraclitos (535-475 BC) thought it was fire, until Empedocles (493-443 BC) ) He is a student of Pythagoras. He is deeply influenced by Bishop s mathematics and believes that the number 4 has the most special meaning. Therefore, he added an element soil and advocated the four-element theory. Water, gas, fire, soil.

By the time of Hippocrates (460-377 BC), the "Four Elements Theory" had developed into a humoral pathology, the first to introduce philosophical ideas into medicine and liberate medicine from mystery and magic. It has four basic concepts:

(1) The entire universe is composed of four basic elements (water, gas, fire, and earth) with specific properties (wet, dry, hot, and cold);

(2) Pairs of opposite forces must be balanced to achieve the harmony of the universe and the health of the small universe of the human body (this concept is accompanied by an emphasis on the number 4);

(3) Seasons have a special impact on a person's body and mind (originally three seasons and later divided into four seasons);

(4) The body's visible secretions were originally three (blood, mucus, and bile). Later, bile was divided into yellow and black into four. Hearst claims that the most important fluid in the body is fluid. All body fluids are made up of different proportions of blood (hot and wet), mucus (cold and wet), yellow bile (hot and dry) and black bile (cold and dry). consist of.

When these "liquids" are properly matched, it is healthy eucrasia, otherwise it will cause disease dyscrasia. There are three stages of the disease:

(1) During the indigestion period, the proportion of liquid changes due to internal or external factors.

(B) The digestive body reacts to this change with a fever or boiling heat.

(3) During the excretion period, excess fluid is discharged at a critical moment to end the disease or death. Later Greek Herophilos (280 BC) applied this doctrine to his treatment, using bloodletting and strong drugs to encourage patients to drain excess body fluids.

During the same period, a second philosophical idea also gradually entered medicine. Anaxagoras (460-356 BC) advocated that each element is composed of many small to invisible particles, which are digested by It is released from food and is again organized into body components like bones and muscles. This theory was later developed by Democritos (460-365 BC) into the "atomic theory", claiming that any substance is composed of atoms of different sizes, weights, shapes and positions. Later Eraistratos (250 BC) also agreed with the idea that atoms are the basis of body structure.

By the time Asclepoades (120-70 BC) of Yascree sent the Greek civilization to Rome, he believed that the human body was made up of atomic dissociation. If the atom did not operate properly, it would be a disease. This idea is called solidism because of its emphasis on solids.

Due to the opposition between these two theories, in the first century before and after the AD, many schools of thought blossomed, including the Dogmatic school, the empirical school, the Methodist school, the Pneumatic school, and the eclectic school. In the midst of these sectarian attacks and disputes, Rome gradually embarked on the path of corruption and destruction.

However, Galen (131-201), the first ancient doctor in ancient times, appeared at this time. Among his 500 well-known books, 83 medical papers were completely passed down. Due to the instability of the Middle Ages, a desire for certainty, people could not learn from their own observations, and lived "by faith", so Glenn's autocracy, lesson, and even showy style, Exactly in line with the desire for absolute things at the time, he did not leave any questions unanswered.

In addition, Glenn repeatedly used "teleological" reasoning, which was easily adopted by the Christian Church. Therefore, everyone regarded him as a god and worshipped him. His influence lasted for nearly 1,500 years. His The work became a ready-made source of medical information.

Glenn follows the pathology of Hippocrates, but pays special attention to blood, thinking that blood is made of a mixture of four elements, and if it is not mixed properly, it will become a disease. In addition, a kind of reiki pneuma is assumed, which is the maintainer of vitality, which can be divided into three types: natural Qi (in the liver), vigor (in the heart), and animal Qi (in the brain), and make It is related to anatomy and physiology, and becomes his unique insight.

The earliest inductive description of the characteristics of inflammation Inflammation-redness, swelling, heat and pain, was described inductively by A. Cornelius Celsus (30 BC-38 AD) in Rome. He wrote a large encyclopedia. All the knowledge, of which there are eight volumes of medicine, volume two, three and four deal with pathology, especially the characteristics of inflammation described in volume three, then Glenn added a feature of loss of function. It will not be until the end of the nineteenth century that reasonable doctrines and mechanisms explain these characteristics.

From the time of Glenn's death to the middle of the fifteenth century, it was the Middle Ages of Medicine, and it was also a dark age. The evolution of medicine can be roughly divided into three periods:

(1) Byzantine (Eastern Roman Empire) medical period, its contribution was the establishment of medical school and the immortal preservation and compilation of medical knowledge. After the fall of Constantinople, Byzantine medicine gradually became;

(2) In the Arab medical era, all streets followed the old Glenn's old saying that due to the admiration of culture, a large number of Greek medical documents were translated. After the fall of the Roman Empire, the dark age of 1,000 years between the flowering of the Renaissance was achieved. There is a trace of bright vitality.

(3) In the European medical era, due to the Crusade's eastward expedition, frequent east-west traffic, all traffic had to pass through Salerno, southeast of Naples, Italy, so it soon became a cultural melting pot and medical center. Constantinus Africanus (1010-1087) was a medical representative of this period. He taught at the University of Salerno most of the time, and translated the Greek texts retained by Arabia into Latin. His works include Hepkra Some collections of Di and Glen, called "Complete Books of Medicine", once again made body fluid pathology the most powerful concept in medieval medicine. Charleno s doctors also classify human temperament into four types according to their main body fluids: 1. People with more blood quality are easier to gain weight and like to laugh; Laziness "; 3, bile people," violent, fierce, easy to get angry "because of the role of hot yellow bile; 4, melancholic people," depressed expression, lack of courage, often feel lonely ", because The reason why cold and dry black bile works. This theory of body fluids did not meet rivals until the publication of Cytopathology by Ruldof Virchow in 1858. Phil Shaw changed this "liquid theory" to a "solid theory", treating cells as the basic composition of the human body.

Due to the expansion of political power, the medical center was also transferred to Bologna and Padua in Italy, Paris and Montpellier in France, Oxford and Cambridge in England ( Cambridge) and other universities. In 1240, Emperor Friedrich II issued a decree, taking anatomy as a compulsory subject for physicians, so only 1316 AD, the "anatomy of Mondino (1275-1325)" "Learning Anatomia" came out, although it was only a book to guide anatomy techniques, not a study of human anatomy. This book was reprinted in forty editions and became the standard textbook before Vesalius was born.

The development of European medicine continued until the 15th and 16th centuries, because after the Renaissance, all academics became lively, humanism gradually rose, and the outlook on life after birth was gradually replaced by the outlook on life after joining the WTO. In the field of philosophy, there is a need for a free study of truth. Descartes of France advocates theoreticalism and emphasizes the importance of experiments. Bacon advocates empiricism and proposes "inductive method" to supplement the deductive method. Kant Kant, Fang Comprehensive Dacheng, set up a new system of modern philosophy. Scientifically, Copernicus, the Polish, established the doctrine that the sun is the center of the universe; Kepler, the German, put forward the theory that planets orbit the sun in elliptical orbits; and Newton, the British, discovered the great law of gravity. Columbus' discovery of the New World and the invention of typography were major discoveries of this period.

Careful observation, autonomous research, and the tendency to rely on the laws of nature are the reasons why modern medicine has flourished. Artist Leonardo da Vinci (1452-1519) made a series of sketches and notes on the structure and function of the human body, combining art and anatomy. In fact, Da Vinci was the first person to doubt Glenn. His research on the heart and blood vessels reached different conclusions from Glenn. He found that the valve only allowed blood to flow to one side, but unfortunately did not elaborate further.

Modern medicine can be said to have begun in 1543 AD. In this year, 28-year-old Andreas Vesalius (1514-1565) published the first complete textbook of human anatomy: "Human Anatomy". Throughout medical history, this is the most meaningful and arguably the most beautiful textbook. He overthrew the traditional Glenn's Miao said that it was because Glenn's narrative was based only on the anatomy of lower animals such as apes and goats. Weiss's anatomy is gradually becoming the basis of all medicine.

In the sixteenth century, several well-known physicians are worth mentioning, such as Paracelsus (1493-1541). He blatantly opposed the immortal physician's wishful attachment to Hemodecratic and Glenn and despised him. The traditional attitude and promotion of continuous innovation based on experiments can be said to be the pioneers of the medical revolution. Parsons is the first person to advocate that medicine should be based on extensive natural knowledge. He believes that the human body is a form that integrates all the natural laws of the outside world. It is a small universe that corresponds to the big universe. Girolamo Fracastoro (1484-1553) in Italy is arguably the earliest epidemiologist. In 1546, he published a book entitled "On Infectious Diseases", which proposed that infections caused by contact with air and the exclusion of Glenn's body fluids caused fever and fever. In the era when the microscope was not yet invented, his theory was quite accurate. In 1530 AD, he published another set of books about syphilis, including three volumes, including the famous syphilis poem. The word Syphilis comes from this poem. The original patient's name was Sypylus, which was a Herders.

After the end of the sixteenth century, people's minds have changed greatly with the arrival of the new century, especially the University of Padua, Italy, which gradually blossomed after the seeds were sowed by Wesalius. First, It was Columbus Realdo Colombo that successfully demonstrated that blood flows from the heart to the lungs, and then from the lungs back to the heart. Later, Gabriel Fallopio discovered the female fallopian tubes and named them in his name. When Fabriziu Girolamo Fabrizio took over, he discovered a venous valve, and eventually a very talented man appeared among his students, named Willian Harvey (1578-1658). After graduating from the University's Caius College, he couldn't wait to study at Padua University. He received a doctorate in medicine from Padua University in 160 AD. Parthia's training fascinated Harvey with his anatomy, and he advocated direct observation and experimental proof to solve the dynamic concepts of pulse and breathing. In Harvey's time, Glenn's anatomy was still deeply rooted. Glenn believes that the digested food is refined into blood in the liver, and then runs through the blood vessels in a mysterious back and forth motion. In this operation, part of the blood flows into the right heart, and then flows into the left heart and then to other organs through the small hole in the middle. At the same time, he claimed that the blood from the heart flows to the lungs. This air can dissipate and maintain the temperature of the blood, and also provides the "vigor" required by the blood to control its biological functions.

What Glenn's theory has troubled Harvey is: Where does the large amount of blood discharged from each heartbeat come from? Coming from food? Or is it produced by continuous manufacturing? Harvey assumes that the volume of blood ejected each time when the heart contracts is two pounds and two pounds. If a person beats heartbeats 72 times per minute, he will lose 8640 pounds per hour. It seems impossible to produce so much blood every hour. The logical reasoning is that the ejected blood must pass through certain blood vessels and then be sent back to the heart, so the blood vessels returned to the blood are only veins. What remains to be proven is the question of whether venous blood will always flow to the heart. The vein valve discovered by his teacher Fabrizio Fabrizio at the University of Padua came in handy. Harvey did a simple experiment and observation to solve the problem: he squeezed it down with a stick. In the veins of the hand, the arrangement of the venous valves was found to make it almost impossible for blood to flow to the ends. In this way, Harvey discovered the secret of human blood circulation, overthrowing the claims of Glenn and others who have dominated for thousands of years, and believed that blood circulates in the closed blood vessel system, and the heart septum has no small holes but small circulation through the lungs. After absorbing air, it flows back into the heart, and finally recirculates the whole body. In 1628, he published these views in the book "Heart Movement." An obvious flaw in Harvey's theory of blood circulation is how blood flows from arteries to veins. This loophole will not be filled until the microscope is released.

The microscope is arguably the most important discovery in the development of medicine and general science. In ancient times, it was known to use polished lenses as magnifying glasses, and spectacles were manufactured in the Middle Ages. A Dutch manufacturer, Zacharias Janssen, tried to combine several lenses to increase the magnification. The first dissertation written using a microscope was completed by Francisco Stelluti in 1625 AD, which is about studying the structure of honey. The microscope at that time was very rough and the magnification did not exceed ten times. It was not until Anthony von Leuwenhook (1632-1723) in the Netherlands that a microscope with a magnification of 270 times was produced. Lei was a cloth dealer and had not attended college, but his passion for microscopes was crazy. He was the first person to recognize hemorrhages (Malpigi mistakenly recognized blood cells as "fat globules") and did sperm. Careful study, but also noticed the striated muscle appearance.

In 1661, the Italian anatomist Marcello Malpighi (1628-1694), after observing the lungs and mesentery of a frog, finally found that the peripheral arteries and veins consist of a hair-like diameter. The tiny blood vessel network is connected, and the capillaries are named as Capillaries, thus filling a loophole in Harvey's theory, and the blood circulation theory is thus completed. At the same time, he was also known as the "Father of Micromedicine". ^[2]