Wednesday, November 20, 2013

120-200 A.D. Galen becomes first pathologist

This was essentially how Claudius Galen was perceived during the middle
ages, where his word on medicine was considered as the final word. 
As a student, and later as a physician, Claudius Galen of Pergamum would study the human body, speculating about what caused a person to be healthy, what caused a person to become sick, and how to cure sickness.  He came to conclusions phland reported his findings to his fellows through his many writings.

It is said by many historians that Galen became an eclectic physician, meaning he incorporated the best ideas of both schools of medicine: dogmatism and empiricism. Some say that he wasn't even an empiricist at all but simply an independent thinker, blending all the best ideas he learned from the sages as he traveled the world with his own ideas. 

Yet first he had to learn about the great physicians.  From Stratonicus he learned to appreciate the theories of Empedocles, Hippocrates and Aretaeus.  From Aeschrion he learned to temper speculation in lieu of experience. (1, page 149)  Many credit him with giving birth to experimentalism, or rationalism. 

Like Aretaeus, he believed a vital force called pneuma was inhaled to the lungs, stored in the heart, and circulated through the body by the vessels.  He was the first to prove that arteries contained blood as opposed to air, although he believed that blood contained a vital spirit that influenced all the organs of the body. 

Galen believed that the body was a perfect machine created by god.  He believed that all parts of the body, from the largest organ to the minutest detail...
...have all been determined by a faculty which we call the shaping or formative faculty; this faculty we also state to be artistic—nay, the best and highest art—doing everything for some purpose, so that there is nothing ineffective or superfluous, or capable of being better disposed. (11, pages 24-27)
By this simple drawing of Galen's you can see how he
believed the body was a perfect machine created by God.
 The liver and veins provided natural spirit and nutrients to
the body.  The heart and arteries provided vital spirit and
passions to the body.  The brain and nerves provided animal
spirit, sensation and intelligence to the body.  
The following is a Galen-made-easy version of how it all worked.  You can determine for yourself if he was a true pathologist,or just a theorist.

He believed there were two basic forms of life: (11, page 2)
  1. Soul: Provides voluntary motion, which is particular to animals 
  2. Nature: Provides growth and nutrition, which is particular to plants and animals (11, page 2)
The two forms of life are ultimately responsible for the two basic effects of nature: (11, page 2)
  1. Animals: Are governed at once by their soul and their nature
  2. Plants:  Are governed by nature alone, not the soul. (11, page 2)
So Galen, therefore, gave us the two following definitions: (11, page 17)
  1. Effect:  The result of the faculty, i.e. veins, blood, nutrition, growth, health
  2. Faculty: The cause of the effect, i.e. the soul and nature make life, the veins and liver make blood, the blood makes nutrition, nutrition is assimilated into the organ to make growth, and adequate growth assures continued life as long as possible, or good health.  (11, page 17)
It's actually quite simple once you think about it. As noted by Galen:
The effects of nature, then, while the animal is still being formed in the womb, are all the different parts of its body; and after it has been born, an effect in which all parts share is the progress of each to its full size, and thereafter its maintenance of itself as long as possible. The activities corresponding to the three effects mentioned are necessarily three -- one to each -- namely Genesis, Growth and Nutrition." (11, page 17)
So the three principle faculties of nature are, according to Galen: (11, page 18-19, 33)
  1. Genesis:  This is the activity (alteration and shaping) of nature necessary to form effects such as bones, nerves, veins, arteries and organs necessary for the formation of the animal or plant as a whole
  2. Growth: The increase and expansion in length, breadth and thickness of the solid parts of the animal
  3. Nutrition:  The addition to the parts without expansion. It is the substances held in the blood that are assimilated into the various parts of the body for genesis and growth. In other words, nutrition is the nutritive faculty that causes the effect of genesis and growth. (11, pages 18-19, 31)
So Genesis, Growth and Nutrition are the first or principle faculties that are responsible for forming and shaping the various parts of the body.  In order for the body as a whole to function properly of these primary principles needs the help of the other principle faculties, and they also need the help of other faculties of nature, such as the faculty of breathing, of making blood, of motion of the blood, etc. 

He believed that food was ingested and went to the stomach.  The stomach cooked most of the food and turned it into chyle that was sent to the liver through veins. The uncooked food went to the intestines to be removed as waste.  The liver and veins turned the cooked food or chyle to blood that contained a natural spirit and nutrients that were vital for growth. (9, pages 58-60)(11, page 13)

This blood was transported by the veins to the right ventricle of the heart to be purified. Here blood was turned into a light, frothy substance that entered the lungs. Once returned to the right ventricle, this purified blood was transported through the venous system to nourish the various parts of the body (such as the organs).   (9, pages 58-60, 89)

Like Hippocrates before him, Galen believed in specific selection, whereby each organ had the ability, and therefor the affinity, to assimilate the exact nourishment it needed from the blood in order perform it's natural function for the body as a whole. (10, page xxvii, xxiv, 31, 49)

Some of this blood moved from the right ventricle to the left ventricle through invisible pores. Here the blood was mixed with the pneuma that was inhaled, and it became vital spirit.  This vital spirit contained passions (such as anger, revenge, courage, desire, happiness, satisfaction, and confidence), and was supplied to the various organs of the body through the arterial system. (9, page 58-60, 87)

Some arterial blood went to the brain, where it was supplied with animal spirit, which contained sensation and intelligence.  This animal spirit was sent through the body by the nerves.  (9, page 58-60)  This animal spirit was essentially what made animals, and humans, different from plants.

So you an see that in order for the nutrients of the blood to be properly absorbed and made useful for purposes of genesis and growth, various organs were necessary.  Each organ uses the faculty of nutrition to stay healthy in order to perform their own faculties of nature.  For instance, the heart assimilates the faculties of nutrients it needs to perform its faculty of mixing air and pneuma with blood, and the liver assimilates the faculties of nutrients it needs in order to perform its faculty of assisting veins turn chyle into blood. (11, page 33-34)

It must be understood that Galen had no concept that the blood circulated through the body, instead he believed the blood moved in a to-and-for movement.  For example, purified blood was transported from the right ventricle to the liver and then back to the right ventricle.  It moved from the right heart to the brain and back to the right heart.  It moved from the left ventricle to the brain an then back to the left ventricle. (10, page xxxvi)

The lungs had four functions: (9, pages 58-60
  1. Inhale air and pneuma
  2. Allowed air to flow from it to the heart in order to cool the heart
  3. Mixed air with its pneuma with purified blood in the left ventricle of the heart
  4. Acted as filters for the venous blood from right ventricle of the heart  (9, pages 58-60
The heart also had four functions:
  1. Right ventricle acted as filter for venous blood
  2. Left ventricle blended air and pneuma with blood
  3. Created the passions of the body
  4. Controlled the temperature of the body (it was the furnace for the body)
Health and sickness were determined by a separate theory.

He believed in the four elements of Empedocles:  (1, page 164
  1. Fire
  2. Air
  3. Earth
  4. Water (1, page 164
He believed from these were derived the four qualities of the body:
  1. Hot
  2. Cold
  3. Dry
  4. Humid. (1, page 164)  
He believed these were derived from the four humors of the body: 
  1. Blood
  2. Phlegm
  3. Black bile
  4. Yellow bile (1, page 164)
These beliefs were common for the time, and were probably learned from the writings of Hippocrates.

Since God created the body as a perfect machine, each organ functioned perfectly in order to maintain the natural balance. This natural balance was maintained by nature maintaining a natural (albeit unique for each body) balance of the elements, qualities and humors.   (1, pages 163-164)

Galen, like Hippocrates before him, believed nature could be assisted in maintaining this balance through good hygiene, or by doing simple things such as getting regular exercise at the gymnasium, cleansing daily in the baths, wearing clean clothing, sleeping in a comfortable bed, and eating a healthy diet.

Since each person has a unique blend of the elements, qualities and humors, each person will have a unique personality or temperment, which can be seen by the following chart:

                                          The Four Humors of Hippocrates                           
Latin Name
Modern Name
Qualities
Personality/Temperament
Haima
Blood
Red, Hot, Moist
Sanuine
Phlegm
Phlegm
Cold, Humid
Phlegatic
Choli
Yellow Bile
Hot, Dry
Choleric
Melanchia
Black Bile
Cold, Dry
Melancholy
So as a perfect balance of these caused health, sickness was caused when something occurred that threw of this balance, thereby disturbing the pneuma.  Hippocrates believed the body as a whole was sick, and therefore treatment emphasized a general remedy aiding nature to re-establish the natural balance of that person's body.

He believed one organ, or one part, of the body could be sick, and this would throw off the chemistry of the unity as a whole, causing the symptoms that were observed. In this way, Watson said that Galen was the first to link symptoms with a specific organ.   (1, page 168)

Fourgeaud said that as an empiric (many historians figured he was an empiric) he thought diseases had a natural cause: (3, page 23)
As disease, according to Galen, consists in 'vel operationis vel structurae oblaesio,' he urged the importance of tracing the general symptoms to the parts or organs primarily affected.(3, page 23)
For exampleWatson said that inflammation occurred when blood entered an areas of the body that normally did not contain blood.  When such blood combines with phlegm, it becomes "aedematous."  (1, page 169)

So when pure blood enters the lungs it can lead to inflammation of the lungs, or pneumonia. It can also mix with phlegm and cause an accumulation of fluid in the lungs called dropsy or hydropsy.  An accumulation of phlegm may cause the symptoms (diseases) of dyspnea, orthopnea, tachypnea or asthma.

Since the pneuma was formed in the heart, he believed that disturbances in the pneuma could be observed by feeling changes in the pulse.  Galen would have become adept at understanding what a normal pulse felt like, and what constituted a change.

Along with feeling the pulse he would perform a full assessment of the patient.  He would ask questions, and he would study the patient's surroundings.  He would place his ears to the patient's chest to listen to his breathing and his heart.  he would place his hand upon the patient's forehead to feel for a temperature.  But, perhaps most important, he would feel the pulse so as to notice any changes in the pneuma.

If he noticed an imbalance, yet the patient still appeared healthy, he would try to assist nature to maintain good health by treating similars with similars. For example, if a person was phlegmatic, by adding phlegm; if a person was sanguine, by adding blood; if a person was choleric, by adding yellow bile; if a person was melancholy by adding more black bile. This task could be performed by using remedies that contained the desired humor, or, more likely, through improved hygiene (diet, sleep, exercise, cleanliness). (1, page 167-170)

Essentially, as noted by Garrison, he combined the "humoral ideas of Hippocrates with the Pythagorean theory of the four elements and his own conception of a spirit or 'pneuma' penetrating all the parts." (8, page 103)  He likewise incorporated into this the anatomical wisdom learned by the Alexandrian physicians Erasistratus and Herodotus.  (10, page xxxii)

Regarding disease, Bradford said he copied the Hippocratic idea of categorizing all diseases as follows: (7, page 43)
  • Acute (it's happening now) or chronic (it's permanent)
  • Endemic (found among certain people), Epidemic (widespread), or sporadic (randomly occurring) 
  • Produced external (outside the body) or internal (inside the body
  • External causes were air, food, drink, motion, rest, sleeping, walking, retention, excretion, and passion
  • Internal causes were hidden, and set in motion by the external causes (7, page 43)
Regarding cures, or remedies, Galen was the originator of contraria contrariis curantur, or curing contraries with contraries, or opposites by opposites, said Bradford.  For example, if the disease was caused by an increase in the element of phlegm due to an increased in the quality hot and dry, the remedy must consist of the opposite qualities, such as hot, fiery pepper. .(7,page 44)

For instance, since increased phlegm was believed to cause asthma, the treatment would be something that would decrease phlegm.  Since increased blood caused fever, decreasing blood through bleeding was the cure.

Galen, like Hippocrates, believed that each nostrum (drugs, natural remedy, herbal remedy) had a specific humor that it was attracted to or drew from the body. In this way, each remedy was specific to healing the symptoms caused by illness to a particular organ. For instance, purgatives were useful for attracting phlegm from the lungs.(11, page 69-70)

Unlike Hippocrates, who mostly advocated simple cures to assist nature in the healing process, Bradford said Galen was a proponent of nostrums, often recommending, among others cures, things like:
  • Cupping
  • Bleeding for congestion of the blood (dropsy, hydropsy)
  • Purgatives for dyspnea and asthma because they drew out some of the excess phlegm
  • Opiates for pain and to ease the mind
  • Ashes of crabs for hydrophobia." (7, page 44)
Watson said that he tended to use the lancet (perhaps in bleeding) and purgatives to "extremes."  However, while leaches were recommended by Themison and commonly used by Methodists (solidists), he did not recommend them as a treatment. 

While he had experience with sprains, fractures, cuts, and bruises during his time in the gymnasium and coliseum of Pergamum, and with serious injuries during his time with the Roman military, he rarely recommended surgeries.  Although when they were necessary, he performed them with exemplary skill and a gentle hand. (1, page 170-171) (9, page 7)

Most historians acknowledge that he was a voluminous writer, and that many copies of his works were made.  Bradford said that he wrote over 500 treaties, (7, page 43) although most of these works have been lost, many were preserved by future physicians either through copies or simply by plagiarizing his work.

This was a good thing in a way, because while the works of most ancient physicians were lost to time and forgotten, Galen's works were immortalized.  His words were worshiped as the Bible for the next 1300 years, and in this way Greek medicine was saved.

This was bad in a way too, because his words created a paradigm of ideas that enveloped the medical profession until well into the 19th century. This, in effect, slowed down medical progress.  But, as we will see, it did not stop it.

For references and further reading: "120-200 A.D.: Galen becomes world's greatest physician."

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