Monday, January 30, 2012

History of Anatomy

The Greek philosophers, voracious in their curiosity, looking forward to the variety of living things, from the least of 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 clear subdivisions, such as botany, zoology and anatomy. But all concerned with living organisms.

The first person to make a significant contribution in biology is Alcmaeon, living in Crotona in the 5th century. Crotona known to scholars as Pythagoras, but Alcmaeon does not seem to have been at their schools. Alcmaeon was the first scientist known to have practiced dissection in research. The goal is not anatomy, for the benefit 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 a punch to the head can affect the mind, brain concussion, this must be where the reason. With a 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, patients become convicted felons). But Celsus, a Roman writer on medical history, full of zeal to justify the suffering of criminals provide "a remedy for the innocent people of all ages to come.


The influential errors of Galen: the 2nd century AD

The newly appointed head physician of the gladiators in Pergamum, in the year 158, is a native of the city. It's 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 is the dissection of apes and pigs Galen provide detailed information on the medical channel organs. Nearly 100 of the channel alive. They became the basis of a great reputation in medieval medicine Galen, unmatched until the work of Vesalius anatomy.


Through experiments Galen was able to reverse the old beliefs, such as the theory (first proposed by the school of Hippocrates in 400 BC or so, and defended even by doctors of Alexandria) containing blood vessels air - wear it around the body of the heart and lungs. This belief is 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 the 15th century

For centuries the very Christian atmosphere prevailing in medieval Europe is not conducive to scientific inquiry. God knows best, and therefore should - because he created everything. Where knowledge is required, there are 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 friar Roger Bacon was the most frequently cited example, but studies including alchemy and astrology, as well as optics and astronomy. Doubt practically necessary 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. For twenty-five years later, he dissected the body of thirty men, many of them to the morgue at 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 would 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, attend lectures 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 the bodies dissected. Often Wizard can not find the body as 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 theory of the anatomy of Galen, which is still in the orthodox medical profession. Galen made a lot of experiments on great apes. Vesalius 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 had nothing to do with humans. Clearly what is needed is a new account of the human anatomy.

Vesalius himself a duty to provide, illustrated with a series of surgeries and images. Having 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 Fabrica Corporis (body structure). There are seven volumes, including beautiful illustrations engraved on wood. This book is a success, although naturally it enrages traditionalists who followed Galen. Galen's 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, the plates in Vesalius volume is a revelation. For the first time people can scan in their own skin, in a very clear picture of what is hidden.


Harvey and the circulation of the blood: AD 1628

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

This book consists of only fifty-two pages, are also found. His text in Latin. The title is Exercitatio anatomica motu Cordis and animalibus sanguinis ("Function Movement anatomy 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 continues 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 blood vessels are 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 connected to the type of energy to the body (not far from the truth), and blood in the blood vessels of the liver distribute food (less accurate).

With a length of surgery (dogs and pigs to snails and clams), and the logical reasoning process, 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 can be demonstrated, carrying blood from the blood vessels into the right ventricle of the heart, he was sent from there through the lungs into the left ventricle of the heart, and then distribute it through the arteries to return different areas of the body.


After much initial opposition, the argument 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 completing the circuit. But surgery was not enough to show this. It was not until four years after his death that Marcello Malpighi observed the capillaries.

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


Malpighi and microscopy: AD 1661

Marcello Malpighi, a professor of theoretical medicine at the University of Bologna, was 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 prepared 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 the blood flow through the flesh. They are so smooth and so much so that each of our bodies contain more than 100,000 miles of microscopic channels.

With their discovery, the missing link in Harvey on the circulation of the blood was found. For capillary literally link through which the oxygen-rich blood from the arteries deliver energy to cells of the body first, then find a way back into the veins to return 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 teaches glass polishing at a very high precision and clarity (some of them provide 300x magnification), using a simple microscope with a single lens - magnifying glass is actually small and very powerful.

With these instruments, he was able to observe a phenomenon previously too small to see. In 1674, he was the first scientist to give an accurate description of the red blood cells. In 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, published mostly 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 of the animal rule.

His account of the following general chip development from egg to adult anatomy refine practices. His research shows for the first time that living things have a life cycle and minutes generative systems as larger creatures.


Microscopic Anatomy: 17 - 20 th century

The discovery Malphighi 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 microscopic anatomy.


The first steps of the new road to occur 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 discovered 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 coherent cells that process of development of all life (long theme guessed by others, but not solved or shows).

But further along this journey, deep into the center of the living matter, is the discovery of the structure of DNA in 1953.