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Anatomy and Physiology in the Renaissance

Page history last edited by lindsey 15 years, 4 months ago

 Summary

 


Galenic Sources in Anatomy and Physiology

After the renewed legality of human dissection as a part of science and philosophy, there was a sudden development of interest in the fields of anatomy and physiology. Up to this point in time, the Galenic view of the human body was taught in universities by a professor who narrated and supplied the thought and reasoning while a dissectionist supplied the model. According to the Galenic corpus, there is, in the body, a continuous ebb and flow of blood to the liver. From the liver it continues to the ventricles where it is combined with air through the pulmonary veins and is endowed with "vital spirit". Galen also classified three different systems of the body saying they were all disconnected: The veinous system, the arterial system, and the nervous system.

 

 

Renaissance Anatomists

 

Andreus Vesalius

     Andreus Vesalius was born in 1514 in Flanders, Belgium, and is considered a leading figure in anatomy study during the Renaissance. He studied medicine in Paris, later becoming a dissectionist and the Demonstrator of Anatomy at the University of Padua. Galen was considered to be the authority on human anatomy and physiology before Vesalius, but Vesalius noted that Galen's dissections were mostly simian, due to the fact that human dissections were considered taboo during his time. He wanted to reconstruct the Galenic physiology on the human body through the dissection of human material.  Vesalius also removed the barrier between the lecturer and the barber-dissectionist. He advocated a more craftlike approach to medicine and successfully blended the role of the dissectionist with the anatomist. He constucted standard six anatomical tables during the year 1537, which correspond to the human body.  In 1543, Vesalius published his work ,The Fabric of the Human Body. In this masterpiece of both science and art, Vesalius sought to make a full study of anatomy on the Galenic model.  Following the structure of Galen's, On Anatomical Procedures, he addressed about 300 errors he found in Galen due to his predecessor's inability to utilize human dissection.  His works were Galenic in organization in that they maintained venous and arteriole systesm. 

 

Michael Servetus

Michael Servetus wrote, Restitution of Christianity, which developed a theory of circulation that brought about the knowledge of the lesser circulation of the blood.  This idea included the theory that blood is pumped from the heart to the lungs and then back to the heart from the lungs.  Servetus' ideas did not reach popularity though as some of his other heretical ideas caused him and all his works to be burned at the stake in 1553. 

 

Realdo Columbo

Realdo Columbo reached the same conclusions about the lesser circulation of the blood as Michael Servetus, but it was his work that was widely known and distributed throughout Europe 

 

Heronimus Fabricius

A professor at Padua, a university noted for its study of anatomy, Heronimus Fabricius is known for his study on the structure of veins. He discovered that there were valves in the veins of the cirulatory system.  He hypothosized that these valves restricted the flow of veinous blood so there would not be too much blood in one area, such as the feet when a person stands up.

 

William Harvey

     William Harvey (1578-1657) was born to an upper middle class family and was a physician to King Charles I. As he was given access to the royal hunting grounds, he regularly practiced dissection on practically any animal or cadaver he could find. Harvey made three arguments that provided evidence for the circulation of blood throughout the body, not only limited to the three systems as previously believed. First, there was a quantitative argument. Harvey estimated that approximately two ounces of blood could be stored in a ventricle at a time. Assuming that only one or two drams (1 dram=1/8 oz) with every pump of two ounces of blood out of the heart was lost during transit (for nourishment, etc.), within a day the heart would have produced more blood that was possible of being held in the human body. Furthermore, the body would have no way of producing that much blood based on the human diet. This led Harvey to argue that blood was not simply made and used, but cycled around the body.

 

His second argument was an anatomical argument. This involved pinching blood vessels and cutting them in order to see which direction blood flowed. In an artery, for example, if one cuts on the side closest to the heart from the clamp, blood will spurt out, but if one cuts on the other side of the clamp, it just oozes out. The reverse is true for veins, though the spurting is not as intense. This was also a form of ligation, but just performed directly on the heart and it's valves.  He also discovered that the heart pumps blood by contractions, and can be examined through the systole and diastole motions of the heart.

 

Harvey's final argument was an observational argument involving ligation. For this argument Harvey tied off a man's arm to observe the effect that it had on blood flow. This showed Harvey the veins in the lower arm and their valves.  The existance of valves was proved by probing veins from the top of the arm to bottom of the arm.  When probed this way, the probe could not go through the valves, due to their one way flow.  When veins were probed from the bottom of the arm to the top, the probe could pass easily.  To show that the valves directed blood from the hand to the heart, he would push the blood out of the vein and then watch it fill back up when he loosened the band around the man's upper arm. When this was done he could observe that the blood filled the veins from the direction of the hand towards the heart. Harvey also noted a relationship between the sun and the heart, where the sun is important for life in earth and the heart is fundamental for life in a human. William Harvey observed the circulation of the body and through his observations, he theorized a new circulatory system that involves recycled blood and one long chain of circulation between the arteries and the veins.   He believed blood left the heart through arteries and returned to the heart through veins.  Unfortunately, he was unable to show the connection between arteries and veins.  The connection (capillaries) was not discovered until the invention of the microscope in later years. 

 

Primary Sources

 


 

Key Terms and Definitions

De Humani Corporius Fabrici - the master work of Vesalius that completely rethought and anazlyzed the Galenic view of anatomy. Considered a masterpiece of science for its information and a masterpiece of art for its numerous diagrams of the human body with Greek influences.

 

Systole - Contraction of the heart

 

Diastole - Expansion of the heart

 


 

Relevant Links

 

Comments (6)

jonathan stutte said

at 4:47 pm on Nov 12, 2008

put vesalius in there.

Grant Berry said

at 9:42 pm on Nov 12, 2008

I started to add Harvey's arguments. I left the ligation argument incomplete, so someone else can fill it in.

Nicole Hagstrom said

at 7:41 am on Nov 13, 2008

I organized the format and took out the repetition in Vesalius.

jgm829@... said

at 1:17 pm on Nov 13, 2008

I added some detail on Vesalius and fixed some grammar.

Jessica Germer said

at 1:43 pm on Nov 13, 2008

i added some stuff on ligation for Harvey

liz mastroianni said

at 6:51 pm on Nov 17, 2008

fixed some grammer and added some stuff

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