"Dispel from your mind the thought that an understanding of the human
body in every aspect of its structure can be given in words; the more thoroughly
you describe the more you will confuse... I advise you not to trouble with words
unless you are speaking to blind men." Leonardo da Vinci
Western and Eastern traditions
We follow the western tradition that evolved first in
Europe
In different regions of the west, perspectives
sometimes differ
Other traditions in the middle east and far east evolved
at roughly the same time and only now are coming together to form a
shared perspective
Latin
language
Latin,
the language of the ancient Roman Empire, became the primary
language of scholars in the west until the 20th century, because
everyone who could read learned to read Latin before their own
language
Most
terminology in science, but especially in human biology, is
therefore Latin in origin and usage
Latin
borrows much from the ancient Greek language, and therefore so
does scientific terminology
Word
parts
root
- main part of the word
prefix
- word part added to the front of a root
suffix
- word part added to the end of a root
Example:
postsynaptic (root is "-synapt-"
prefix is "post-"
suffix is "-ic")
Parkinson
disease is proper whereas
Parkinson's disease is improper (in the AMA style)
Required
reading: Read p. 1 & 2 of the Quick
Guide to the Language of Science and Medicine, which the
pamphlet is inserted in your copy of Anatomy
and Physiology6th edition for a cartoon and explanation of MRI
Culture is different among different
peoples at the same time
Culture influences the way we see the world and
ourselves; it shapes the way we think
Culture influences the way we look at the human body,
what questions we ask about it, and how we answer those questions
For example, whether or not cadavers (human remains
used for study) are dissected or not has depended upon the norms of
the culture: it is acceptable and encouraged
now, but not during the
middle ages
It has been acceptable to use animals for live
experimentation but that may be changing right now in our own
culture
A Traffic of Dead
Bodies: Anatomy and Embodied Social Identity in Nineteenth-Century
America, a book by Michael Sappol,
explores the cultural tensions created by the use of dead bodies
sometimes acquired by grave robbery and the public's desire for
"anatomically trained doctors."
Some
ethical questions . . .
A famous textbook of human anatomy, Pernkopf
Anatomy, Atlas of Topographic and Applied Human Anatomy (2
volumes) by Dr. Eduard Pernkopf, features stunning artwork of
cadavers and is considered a valuable classic in understanding the
human body. However, there is good evidence to indicate that
some of the cadavers used as models for this book were victims of the
Nazi holocaust that were dissected at Dr. Pernkopf's lab at the
University of Vienna, where the book was produced. A debate that
has been raging since the mid-1990s centers around whether the book
should still be used, considering the source of some of the
cadavers. For more information, see NIH Record - 09-24-96 -- Anatomy Text Draws Criticism
or InSCIght - 26 November 1996 Anatomy Text Linked to Nazi Victims (not required).
Assuming it contains useful
illustrations, do you think the book should still be used?
The Visible Human Project sponsored by the NLM (National
Library of Medicine) is an ongoing effort to use modern imaging
techniques with cadavers to produce digital data that can be used for
a variety of research and educational purposes. The first body
used in the project, the Visible Man, belonged to a man executed by
U.S. government
Considering the fact that a
significant number of people are opposed to execution, do you think
there are ethical concerns about using images from the Visible Human
Project?
Gunther von Hagens has created an exhibit of dissected and plastinated human
bodies called Body Worlds.
Plastination converts tissues into
durable plastic by chemical processes and is used with increasing
frequencies among today's anatomists. Unlike most anatomists,
however, van Hagens has depicted his specimens in active, sometimes
provocative, positions. For example, a human body playing
basketball. His work has created an ethical firestorm. Some
believe that the body should not be represented in an artistic manner,
while others argue that such artistry has been the tradition of scientific
dissection.
What you do you think
about Body Worlds? Is it ethical to exhibit human bodies in public
in this manner? Does it serve education or science, or is it
strictly asthetic?
Mary Roach's book
STIFFS is a humorously written but
scientifically accurate description of what happens to the human body
after death. It includes a chapter on the educational/anatomical
uses of human bodies.
Highly recommended reading!
Major thinkers in the western tradition
Aristotle (384-322 BCE)
of Greece
Along with his contemporary
scientist-philosophers, Aristotle thought arteries contained air and
veins carried blood. He had other "strange" ideas but
was roughly accurate as far as the general anatomy of the human
body.
Recognized
that bodies are made of parts, which in turn are made of simpler
parts
Recognized
that similar organs in different organisms probably have similar
functions
Thought
the brain cooled the body and the heart heated it
Thought
that the heart was the location of the mind, will, and emotions
Aristotle and others of his era did not rigorously question
observations, as we do today.
From
Aristotle's History of Animals (Chapter XIV):
". .
. the heart is placed in the center; in man it is rather on the
left side, inclining a little from the division of the mammae
towards the left breast in the upper part of the chest; it is not
large; its whole form is not long, but rather round, except that
the extremity ends in a point. It has three cavities, as I
have said. The greatest is that ton the right, the least on
the left, the middle one is of intermediate size. They are
all perforated towards the lungs."
Aristotle Click to enlarge
"All men by nature
desire to know." Aristotle (in Metaphysics)
Claudius
Galen (129-199 CE) of Pergamon (now Turkey) (later, Rome)
Greek physician
in the Roman Empire who performed experiments to prove arteries contain blood (but thought the heart was a single --not
double--pump)
Many of Galen's conclusions were wrong because he used mostly animals
after an early career using humans at a gladiatorial school outside Rome
Human
dissection was forbidden in ancient Rome
From On
Anatomical Procedure (Book I, Chapter II):
"Pursue
by hard study, then, not only the descriptions of the bones in
the book, but also acquaint yourself with the appearance of
each of the bones, by the use your own eyes handling each bone
by itself so that you become a first-hand
observer. . . . I once examined the skeleton of a
robber, lying on a mountain-side a short distance from the
road. This man had been killed. . . and his body was
eaten by birds of prey. . . As regards yourself, then, even if
you do not have the luck to see anything like this, still you
can dissect an ape, and learn each of the bones from it."
Galen was considered "the authority" until the Renaissance
During
the Middle Ages, questioning Galen was questioning authority and
because authority came from God, it was heresy and punishable by
death --so NOBODY questioned Galen's conclusions
Diagram of Galen's concepts
Galen
treating a patient
(Click to enlarge) In the painting to the left, Galen is shown
"cupping" a patient. In this procedure, heated cups are
applied to the patient's back. As the warm air in the cups cools,
the air contracts and forms sucking force that draws blood toward the
surface of the skin. Sometimes, cuts in the skin allow the cupping
procedure to draw out the blood (a treatment known as
blood-letting). Cupping was probably borrowed from the Eastern
tradition and is still used
today by some traditional healers.
"Employment is
nature's physician" Claudius Galen
Andreas Vesalius (1514-1564 CE) of Brussels
(later Padua, Italy)
Flemish
anatomist willing to "use his own eyes" in human dissections correcting over 200
mistakes of Galen
During the
middle ages, everyone had simply trusted Galen, but Vesalius and
others during the Renaissance began to question and correct Galen
Vesalius
was one of the first to dissect cadavers himself (rather than rely
on others or on animal dissections); even Leonardo da Vinci and
other "artist-anatomists" didn't do their own dissection
(of course, they lived nearly twice as long because they weren't
exposed to infections in the dead bodies)
Vesalius
was obsessed with dissections, even stacking up cadavers in his
bedroom as a medical student in Paris. Later in his life, he
told his students to keep a list of their really sick patients so he'd
know where to go to get a freshly dead body (yikes)
This book was published the same year as Copernicus's text, marking this
year as the beginning of the "Scientific Revolution"
"It
is perfectly clear to me that my attempt will have all too little
authority because I have not yet passed the twenty-eighth year of
my life; it is equally clear that, because of the numerous
indications of the false dogmas of Galen, it will be exceedingly
unsafe from the attacks of conservatives, who, as with us in the
Italian schools, have constantly avoided anatomy, and who, being
old men, will be consumed with envy because of the correct
discoveries of the young, and will be ashamed at having been blind
thus far, along with other followers of Galen."
Medieval dissection - notice that the professor
oversees the dissection and the dissector does the cutting Click image to enlarge
Vesalius - Notice that Vesalius has
come down from the podium
and does his own dissections
". .
. blood does pass through the lungs and heart by the pulse of the
ventricles, and is driven in and sent into the whole body, and
does creep into the veins and porosities of the flesh, and through
them returns from the little veins into the greater, from the
circumference to the centre, from whence it comes at last into the
vena cava, and into the ear of the heart in so great an abundance,
with so great flux and reflux, from hence through the arteries
thither, from thence through the veins hither back again, so that
it cannot be furnished by those things which we do take in, and in
a far greater abundance than is competent for nourishment: It must
be of necessity concluded that the blood is driven into a round by
a circular motion in creatures, and that it moves perpetually; and
hence does arise the action and function of the heart, which by
pulsation it performs; and lastly, that the motion and pulsation
of the heart is the only cause." (Aren't you glad
Harvey didn't write your textbook!)
Figure below shows one of many experiments that Harvey documents in his
thorough proof that the heart is a double pump and how blood
actually circulates.
Harvey is
credited with beginning modern physiological research and
experimentation
Harvey's experiment
William
Beaumont (1785-1853 CE) of the United States (eventually, St. Louis)
Beaumont was an American army surgeon who, while stationed in
Michigan, treated the 18-year-old Canadian Alexis St. Martin after an
accidental short-range shotgun blast
"August 1, 1825. At 12 o'clock M.,
I introduced through the perforation, into the stomach, the
following articles of diet, suspended by a silk string, and
fastened at proper distances, so as to pass in without pain--vis.:
a piece of high seasoned a la mode beef; a piece of raw,
slated, fat pork; a piece of raw, salted, lean beef;
a piece of boiled, salted beef; a piece of stale
bread; and a bunch of raw, sliced cabbage; each
piece weighing about two drachms; the lad continuing his usual
employment about the house.
At 1 o'clock p.m.,
withdrew and examined them--found the cabbage, bread, pork,
and boiled beef about half digested; the other
pieces of meat unchanged. Returned them into the
stomach.
At 2 o'clock p.m.,
withdrew them again--found the cabbage, bread, pork,
and boiled beef, all cleanly digested, and gone from
the string; the other pieces of meat but very
little affected. Returned them to the stomach again."
"This experiment is important, in a
pathological point of view. It confirms the opinion,
that undigested portions of food in the stomach produce all
the phenomena of fever; and is calculated to warn us of the
danger of all excesses, where that organ is concerned."
Some controversy later developed over the use of
human subjects; St. Martin kept returning for more experiments when he
needed money, even going down to St. Louis occasionally after Beaumont
moved there
Beaumont is credited for being a pioneer in rigorous
experimentation and detailed observation
FYI After retiring from the army, Wm. Beaumont was
asked to be the first head of St. Louis University's Medical School
but he refused. He did leave a legacy to the school,
however, and the SLU medical school was at one time named for him.
"The true worth of an experimenter consists
in his pursuing not only what he seeks in his experiment, but also
what he did not seek."
Validates knowledge from proving hypotheses
wrong
Bernard also made groundbreaking discoveries in the
function of pancreatic juice, the existence of muscle that control
blood vessel dilation, actions of curare and other drugs in
neuromuscular function, and liver function
Bernard also was the first to articulate the concept of "relative
constancy" of the body --or homeostasis-- a topic discussed in the Mini
Lesson: Homeostasis.
Claude Bernard
"Art is I; science
is we." Claude Bernard
Modern times
The 2003 Nobel
Prize in Physiology or Medicine was awarded to two scientists for a
breakthrough in the way that the way that the human body is studied:
Imaging of
human internal organs with exact and non-invasive methods is very
important for medical diagnosis, treatment and follow-up. This year's
Nobel Laureates in Physiology or Medicine have made seminal discoveries
concerning the use of magnetic resonance to visualize different
structures. These discoveries have led to the development of modern
magnetic resonance imaging, MRI, which represents a breakthrough in
medical diagnostics and research.
Atomic
nuclei in a strong magnetic field rotate with a frequency that is
dependent on the strength of the magnetic field. Their energy can be
increased if they absorb radio waves with the same frequency (resonance).
When the atomic nuclei return to their previous energy level, radio waves
are emitted. These discoveries were awarded the Nobel Prize in Physics in
1952. During the following decades, magnetic resonance was used mainly for
studies of the chemical structure of substances. In the beginning of the
1970s, this years Nobel Laureates made pioneering contributions, which
later led to the applications of magnetic resonance in medical imaging.