Introduction to Cell Theory and Microlife

1. Introduction to Cell Theory and Microlife You will build an understanding of cell theory and cell function You will understand the IMPACT of microorganisms

2. Western Concept of disease • What is a disease? • Disease is the ABNORMAL FUNCTION of a cell, organ, or a body system

3. 4 Main Milestones: Western Concept of Disease • Prehistoric Times (before Greek Civilization) • Disease- was caused by the supernatural. Disease was caused by the punishment of “gods”, sorcery by one’s enemy, spiritual possession (evil), or loss of soul

4. 4 Main Milestones: Western Concept of Disease • Treatment- performed by “healer” or medicine man or clergy. These people held high status since they not only healed but were also thought to have powers that aided in harvest, weather and even aid in battles. Practice continued well into 19th century by Native American Indians

5. 4 Main Milestones: Western Concept of Disease • Positive Outcomes (3) • Practice of “herbal medicine” plants still used today as source of new medicines/drugs • Opium as pain killer • Honey as wound healer: primitive antibacterial agent

6. 4 Main Milestones: Western Concept of Disease • Negative (1) • Trephination- (used by all societies around the globe) was procedure of boring a hole into a patient’s skull to release demons. Surprisingly some patients survive (see bone re-growth in image)

7. 4 Main Milestones: Western Concept of Disease • 2. Greek Civilization brought about new ideas about disease • Hippocrates (460 B.C.) believed that all diseases had a NATURAL CAUSE and by careful OBSERVATION and ATTENTION to detail the cause of the disease COULD BE FOUND. From this treatments and cures could be made as well! • Wrote series of 50-70 books called “CORPUS HIPPOCRATUM” these books can be used today still to diagnose diseases. Dr’s take Hippocratic Oath in honor of him today!

8. 4 Main Milestones: Western Concept of Disease • Aristotle (384 B.C.) great philosopher and scientist but had huge NEGATIVE IMPACT on medicine. Believed disease was caused based of the 4 “humors” or liquids of the body. • Disease occurred when body had an imbalance of the 4 humors: too much or too little of one or more of these liquids (see chart)

9. 4 Main Milestones: Western Concept of Disease • Treatment- for a fever (hot/dry disease) you would be placed in cold bath (wet/cold) for body to more Phelgm. • For cold (wet/cold) you would be wrapped in heavy wool garments and forced to drink wine (warm/dry) to produce more Yellow Bile • Aristotle’s findings “perfected” by the famous Roman “Dr.” Galen (130 A.D.) He began practice of blood letting and body evacuation to assist in treatment of the imbalance.

10. Greek Outcomes Positive- Hippocrates methods provided blueprint of diagnosing and treating disease Greek Outcome Negative- Adherence to “4 Humors” approach to medicine causes people not to look for specific causes of disease. This failure persists until the 16th century (1500’s) 4 Main Milestones: Western Concept of Disease

11. 4 Main Milestones: Western Concept of Disease • 3. Middle Ages and the Renaissance • Fall of Roman Empire leads to period of 1000yrs with little change in peoples’ understanding of disease. “Galenic” medicine is heavily practiced with 4 humors renamed as phelgmatic, choleric, sanguine, and melancholy. • Aristotle’s affect on science can be seen here as well by his idea of Spontaneous Generation. • Spontaneous generation was the idea that life came from no life. (came from Aristotle seeing piles of trash “grow” maggots, flies, and mice.) This idea stays popular well into the 1870’s! • Astrology returns in having a role for disease as well as the supra-natural forces (medicine practices go backwards!!!!)

12. 4 Main Milestones: Western Concept of Disease • 1546- Turning Point: 1546 major plague strikes Europe again. An Italian Poet writes of a “contagion” being passed from one infected thing to another. Idea reopens people’s minds • Later the “Miasma” Theory comes about; Miasma theory stated that “Miasma” was given off by diseased and decaying bodies • Outcome: If exposed to the “miasma” you could get the disease: REJECTS ARISTOTLE theory and returns focus back to HIPPOCRATE’S theory

13. 4 Main Milestones: Western Concept of Disease • The Enlightment (1800’s - today) • Beginnings of Enlightment period go back to 16th century with Scientists such as Da Vinci and Vesalius question the “Galenic” medicine practices of their day based off their studies of human cadavers

14. 4 Main Milestones: Western Concept of Disease • 1847 Ignaz Semmelweis proves that blood poisoning could be carried by doctors to their patients. If physicians washed hands before treating patients blood poisoning was stopped • 1853-54 John Snow proves that contaminated water was cause of cholera epidemic in London: “Bad” water could cause disease!! • 1857 Louis Pasteur- first to suggest micro-organisms were cause of human illnesses: MODERN STUDY OF DISEASE begins! Pasteur becomes well known for the use of heat to kill micro-organisms now called Pasteurization

15. 4 Main Milestones: Western Concept of Disease • 1857 Louis Pasteur- first to suggest micro-organisms were cause of human illnesses: MODERN STUDY OF DISEASE begins! • Pasteur becomes well known for the use of heat to kill micro-organisms now called Pasteurization

16. 4 Main Milestones: Western Concept of Disease • Robert Koch 1858- Prussian Scientist (hated Pasteur his rival) proves that a specific bacteria was cause of anthrax. Develops procedure for identifying disease agents • 1. To relate microbe to a disease the microbe must be found on all cases of the disease • 2. The microbe must be isolated and grown in a pure culture • 3. The disease must develop in organisms exposed to the microbe • 4. The same microbe must be identified on the diseased organisms

17. 4 Main Milestones: Western Concept of Disease • Feud between Pasteur and Koch leads to the following discoveries of disease causing microbes: Typhoid fever, diphtheria, rabies, tetanus, and tuberculosis • What about Viruses? • Walter Reed (U.S.) 1901-discovers the first “human specific virus” yellow fever: but had no visible microbe • 1940’s first photographs of viruses taken with electron microscope