Thursday, April 25, 2013

History of Anatomy

The Greek philosopher, voracious in their curiosity, look forward to a variety of living things, from the least of the plants to humans. A Greek name was invented by a German naturalist in the early 19th century to study all aspects of the physical nature of life - biology, bios (life) and logos (word or discourse). This is a topic with a clear subdivisions, such as botany, zoology and anatomy. But all are concerned with living organisms.

The first person to make a significant contribution in biology is Alcmaeon, at Crotona lived in the 5th century. Crotona known at the time of Pythagoras to graduate, but Alcmaeon does not seem to have been at their schools.

Alcmaeon is the first scientist known to have practiced dissection in research. The goal is not anatomy, the interest lies in trying to find a place of human intelligence. But in the course of his research, he made the first scientific discoveries in the field of anatomy.

Then the Greek theory, subscribed even by Aristotle, is that the heart is the center of intelligence. Alcmaeon reason that as a blow to the head can affect the mind, brain concussion, this must be where the reason. With post-mortem to pursue this idea, he observed the parts that connect the brain to the eye (optic nerve) and the back of the mouth to the ear (Eustachian tube).


Human vivisection: c.300 BC

At the beginning of the third century BC in Alexandria two surgeons, Herophilus and Erasistratus, made the first scientific study to learn about the workings of the human anatomy.

Cost of their contribution to science would be considered too high in modern times (they get much of their information from human vivisection, the patient became convicted felons). But Celsus, a Roman writer on medical history, suffering criminals vigorously justify providing "medicine for the innocent people of all ages to come.

The error affects Galen: 2nd century AD

The newly appointed head physician of the gladiators in Pergamum, in 158, was a native of the city. It was a Greek physician named Galen. The appointment gave him the opportunity to study the wounds of all kinds. His knowledge of the muscles that allow him to warn patients about the possible outcomes of a particular operation - a wise precaution physician Galen recommended the council.

But it was Galen dissection of apes and pigs which provide detailed information on the medical channel organs. Nearly 100 of the surviving channels. They became the basis of a great reputation in medieval medicine Galen, unsurpassed until the work of Vesalius anatomy.

Through experiments Galen was able to reverse long-held beliefs, such as the theory (first proposed by the school of Hippocrates in 400 BC or so, and maintained even by the doctors of Alexandria) air containing blood vessels - wear them to all parts of the body from the heart and lungs. This belief was based initially on the arteries of dead animals, which appears to be empty.

Galen was able to show that arterial blood contains life. The mistake, which will be established medical orthodoxy over the centuries, is to assume that the blood came and went in the heart of the movement and flow. This theory applies in the medical community until Harvey.

The science of sleep: 8 to 15th century

For centuries a very Christian atmosphere prevailing medieval Europe was not conducive to scientific inquiry. God knows best, and therefore should - because he created everything. Where necessary knowledge, no ancient authorities whose conclusions are accepted without question - the astronomy of Ptolemy, Galen on anatomical matters.

Some scholars showed an unusual interest in scientific research. 13th century Franciscan monk Roger Bacon is the most frequently cited example, but studies including alchemy and astrology, as well as optics and astronomy. Practical skepticism needed for science, not until the Renaissance.

Anatomical drawings of Leonardo da Vinci: AD 1489-1515

At about 1489 Leonardo da Vinci began a series of anatomical drawings. For greater accuracy of observation, they are far more advanced than anything previously attempted. Over the next twenty-five years, he dissected thirty human body, many of them to the morgue in Rome - until in 1515 Pope Leo X, ordered him to stop.

His picture, which is about 750, including studies on the structure of bones, muscles, organs, brain and even the position of the fetus in the womb. His study shows that the heart will find the concept of blood circulation.

Vesalius, and anatomy: AD 1533-1543

A medical student, was born in Brussels and is known to history as Vesalius, following the lecture on anatomy at the University of Paris. Lecturer explains human anatomy, as revealed by Galen 1000 years earlier, while the corresponding data points assistant with dissected corpses. Often Wizard can not find the body that are described, but the body is not always necessary to be one of Galen.

Vesalius decided he would dissect the bodies themselves and to trust the evidence of what was found. The approach is highly controversial. But his apparent ability to cause his appointment in 1537 as professor of surgery and anatomy at the University of Padua.


In 1540, Vesalius gave a public demonstration of the inaccuracy of the anatomy of Galen's theory, which is still in the orthodox medical profession.

Galen made a lot of experimentation on great apes. Vesalius is now on the screen - for comparison - a man and a monkey skeleton.


Vesalius was able to show that in many cases it is true monkey sighting Galen, but it has nothing to do with humans. Clearly what is needed is a new account of the human anatomy.

Vesalius himself the task of providing, illustrated with a series of surgeries and images. Has at its disposal, the method is relatively new in Europe, to ensure a clear division of the image printed form - the art of wood carving. His studies were inaugurated modern science of anatomy.


In Basel, Switzerland, in 1543 Vesalius published his great work - De Humani Corporis Fabrica (The structure of the human body). There are seven volumes, including beautiful illustrations engraved on wood. This book is a success, although naturally it enrages traditionalists who followed Galen. Galen theory is, after all, a clear benefit of seniority. They are now some 1400 years.

But for those who want to see with clear eyes, plates in Vesalius volume is a revelation. For the first time people can scan in their own skins, in a very clear picture of what is hidden.


Harvey and blood circulation: AD 1628

There is a book published in 1628 which provides one of the biggest breakthroughs in understanding the human body - perhaps the largest to the discovery of DNA structure in the 20th century.

This book consists of fifty-two pages, also argued. Its text in Latin. The title is Exercitatio anatomica motu cordis and animalibus sanguinis ("The functional anatomy of the Movement of the Heart and Blood in Animals"). The author is William Harvey. In this book he shows without a doubt, an entirely new concept. Blood, it shows, does not originate in the body of any kind of tidal random. Instead he continued to be pumped around the circuit is very accurate.


So far it has been assumed that the blood in the arteries and blood in the veins is of different nature. It is well known that they are a different color, and there are many theories as to what each shipment of blood.

The most common belief is that arteries carry air to the type of energy connected to the body (not far from the truth), and blood in the blood vessels of the liver distribute food (less accurate).


With a long series of surgery (dogs and pigs to snails and clams), and the process of logical reasoning, Harvey was able to prove that the body contains a single blood supply, and that the heart is a muscular pump about its circuitry.

This circuit, as it can demonstrate, carry blood from the veins into the right ventricle of the heart, he was sent from there via the lungs to the left ventricle of the heart, and then distribute it through the arteries to return various body regions.


After much initial opposition, arguments Harvey finally convinced most of his contemporaries. But there are two missing ingredients. The theory suggests that there should be a network of tiny blood vessels that carry blood from the arterial system and the venous system and complete the circuit. But surgery was not enough to show this. It was not until four years after his death that Marcello Malpighi observed capillary.

And Harvey can not explain why the heart has to pump blood. This explanation must await the discovery of oxygen.


Malpighi and microscopy: AD 1661

Marcello Malpighi, professor of theoretical medicine at the University of Bologna, is a pioneer in the use of the microscope in biology. One night in 1661, on a hill near Bologna, using the sun as a source of light, shining in its goal through thin sections made from the lungs of the frog. In the broader picture, it is clear that all of the blood contained in a small tube.

Malpighi thus became the first scientist to observe the capillaries, the tiny blood vessels in which blood flows through the flesh. They are so smooth and so much so that each of our bodies contains more than 100,000 kilometers of microscopic channels.

With their discovery, the missing link in Harvey on the circulation of the blood was found. For literally capillary link through which oxygen-rich blood from the arteries provide energy to the cell body first, then find a way back into the vein to be returned to the heart.


Leeuwenhoek and microscopy: AD 1674-1683

Pioneering work by Malpighi microscope is also taken by the Dutch scientist Anton van Leeuwenhoek. He taught polishing glasses at a very high precision and clarity (some of them provide 300x magnification), using a simple microscope with only one lens - magnifying glass is actually small and very powerful. With these instruments, he was able to observe a phenomenon previously too small to be seen. In 1674, he was the first scientist to give an accurate description of red blood cells. At 1677, he observed and described sperm in semen dog. In 1683, he gave a picture of animalcules (or bacteria) were observed in saliva and dental plaque.

His findings, which largely published in the Philosophical Transactions of the Royal Society of London (though he himself lived in Delft), strongly suggest the joy of being the first to walk around with such a broad vision of the little things from the animal reign. His account of the following general chip development from egg to enhance the practice of adult anatomy. Study shows for the first time that living things have a life cycle and a minute generative systems as larger creatures.

Microscopic Anatomy: 17th - 20th century

Malphighi discovery capillaries, the anatomy of the main body are known. With a thorough study of Leeuwenhoek previously unseen aspects of living matter, the subject moves to stage a more mysterious - than the microscopic anatomy.

The first steps of a major new road occurred in the 1830s.

Felix Dujardin in 1835 identified as a translucent viscous substance common to all forms of life, the name given by the protoplasm. While others observed that the object of life is set in the form of repeated structural. Robert Brown found in the factory, in 1831, the main nucleus of every cell. In 1839, Matthias Schleiden and Theodor Swann gave the first account of the formation of a coherent cell that the process of development of all life (long theme guessed by others, but not solved or shows). But the further along this journey, deep into the center of the living matter, is the discovery of the structure of DNA in 1953.

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