Oct 25 Anatomy and Physiology
Hippocratic medicine, 450BCE-
Oath
The medical marketplace
Competition for patients, $$
How to establish qualifications and build a reputation?
Ethical standards, selflessness, trust.
Skill at diagnosis and prognosis looks impressive.
Learned doctors base their practices on natural philosophy –better therapies?
Core Hippocratic doctrines (all texts not consistent)
Health = balance (eukrasia)
Sickness = upset, excess/deficiency.
Of bodily fluids = 4 humors.
Blood, phlegm, yellow bile, black bile.
Causes of imbalance may be internal (eg bad diet) or environmental (Airs, Waters, Places).
Medicine maintains, regulates, restores the individual’s correct proportion of humors.
Treatment by opposites.
System of opposites in humoral medicine (On the Nature of Man)
Humors, Elements, Qualities, Seasons, Temperaments
Appealing theory: simple, flexible, can fit any situation, supported by common experience.Yet entirely speculative of underlying reasons.
Theory into practice
Belief in healing power of nature, so physician should act conservatively.Achieve natural balance of humors.
Therapeutics
Regimen = diet, exercise, sleep, sex…
Drugs or foods = e.g. “take something hot,”create opposite effect from your symptoms.
Purging to eliminate excess humors.
Bloodletting.
Intersections of Greek science and medicine
Empirical methods
Carefully observe symptoms, progress of sickness, external influences, lifestyle, etc.
Seeking natural explanations
Reasoning about how human body works.
Plato, Aristotle discuss medical topics.
However, some Hippocratic writers reject all theorizing
Medicine should be an art, not science.
No general theory of disease.
“Certain physicians and sophists assert that it is impossible for anyone to know medicine who does not know what man is, and that to treat patients correctly it is necessary to learn this…”
Medical sects (Hellenistic & Roman)
Empiricists
Only use experience, visible symptoms
Rationalists (dogmatists)
Theory of disease, physiology
Anatomy and Physiology
Speculate on hidden causes of normal bodily processes (physiology).
Leads to knowledge of pathological processes.
Better medical practice? [always the rationale]
Natural philosophy and the human body: Aristotle’s theories
Teleological thinking: structure follows function. Parts exist for the sake of…
Example: what are the lungs for?
What’s breathing for?
To cool the body.
Study, dissect, compare entire animal kingdom = research program at Lyceum.
Plato’s Timaeus describes human physiology [divine teleology, vague]
“The gods, forseeing that all such passion would come about by means of fire, devised support for the heart in the structure of the lung, making it soft and bloodless, perforated by cavities like a sponge, so that by absorbing breath, and cooling by respiration, it might also provide relief in the heat of passion.”
Aristotle summary
Chick embryos research.
Heart & blood primary.
Nutrition
Movement & sensation
Mechanical analogies in his account of innate heat, heart & lungs expand…
Research at Alexandria 300BCE-
Hippocratic medicine.
Influenced by Peripatetic school.
Anatomy –many new discoveries.
Physiology –theories of digestion, respiration, sensation, vessels.
Herophilus 330-260
Erasistratus 304-255
Erasistratus’physiological system (no circulation of the blood until 1600s)
1. Function of blood and veins:
Food ground up by stomach.
Absorbed into liver where it’s converted into blood.
Blood travels thru veins to nourish body (absorbed).
Disease = plethora of blood from overeating, causes inflammation, fever.
2. Function of air and arteries:
Pneuma (vital spirit, soul) inhaled from the atmosphere into lungs.
Travels to heart and it’s pumped out to the body thru the arteries (heart as bellows).
If arteries contain only air, then why do they spurt blood when vivisected? Because “nature abhors a vacuum.”
3. Psychic pneuma and nerves:
Pneuma is refined in the brain to make spirits that are responsible for motion, sensation, thought.
Sent out to body via hollow tubes of the nerves.
Brain is the seat of intelligence, not the heart as in Aristotle.
Human dissection for research & public display
Why Hellenistic Alexandria?
Why not other places & times?
Did Erasistratus and Herophilus also experiment on live human subjects (vivisection)?