Lecture 2 Outline of Last Lecture I. Review of the Course II. Cancer in Relation to Other Diseases III. Leading New Cancer Cases and Deaths Outline of Current Lecture I. The Nature of Disease II. Categorie sof Diseases III. The Scientific Method IV. Experiments and Theories V. Infectious Diseases a. Factors VI. Life Expectancy Current Lecture The Nature of Disease: •Disease: an abnormal condition of an organism that impairs bodily functions -Any condition that causes discomfort, dysfunction, distress, social problems, and or death to the person afflicted, or similar problems for those in contact with the person •Injuries, disabilities, disorders, syndromes, infections, isolated symptoms, deviant behaviors MicroBio 160 1st Edition These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best !used as a supplement to your own notes, not as a substitute. !Categories of Diseases: •Infectious Disease: disorders caused by organisms (bacteria, viruses, fungi, and parasites) -Specific organism or combination of organisms •Genetic Disease: disease caused by abnormalities in an individual’s genetic material -Klinefelter’s syndrome, down syndrome, turner syndrome •Environmental Disease: illnesses and conditions caused by factors in the environment -Molds, cigarette smoke, pollution, lead poisoning The Scientific Method: a well-documented, carefully controlled experiment that applies logic, order, and critical thinking skills to solving problems and finding new information 1. Observation of nature 2. Hypothesis 3. Prediction 4. Te s t A. Support Hypothesis (theory) -Further tests B. Reject Hypothesis -New or revised hypothesis Observations of Cells: •Aristotle: Spontaneous generation— living things can come from nonliving things •Jean Baptist Van Helmont: concluded that mice came from dirty rags and rotting grains•Francesco Redi: challenged the idea of spontaneous generation— setting up a meat and maggot experiment The Meat and Maggot Experiment: -Observation: flies in a butcher shop -Question: Does rotten meat turn into or produce the flies? -Hypothesis: Rotten meat doesn’t turn into or produce the flies. Flies make more flies -Conclusion: Maggots arose only where flies were able to lay eggs (gauze covered and control jars) Thus only flies can make more flies. This experiment disproved the idea of spontaneous generation for larger organisms. •Louis Pasteur: disproved spontaneous generation overall, forming the germ theory of disease and inventing the process of pasteurization -Germ Theory of Disease (pathogenic theory of medicine): Microorganisms are the cause of many diseases— proven by Louis Pasteur •Experiment 1: Boiling kills microorganisms—time—closed flask (traps microorganisms)— no nutrient growth •Experiment 2: Boiling kills microorganisms—break stem—time— microorganisms enter open flask and grow rapidly— microbial growth•Anton Van Leewenhoek: first person to make a single lens microscope and observe single celled organisms •Robert Hooke: first person to design a compound microscope and coined the term cell The Modern Cell Theory: •All known living things are made up of cells •The cell is structural and functional unit of all living things •All cells come from pre-existing cells by division (Process by which a parent cell divides into two or more daughter cells) •Cells contain hereditary information which is passed from cell to cell during cell division •All cells are basically the same in chemical composition •All energy flow (metabolism and biochemistry) of life occurs within cells Infectious Disease: detrimental changes in the health of the host occurs as a result of damage caused by a pathogenic organism •1876: Microbe was proven to cause disease •Robert Koch proved that Bacillus Anthraces caused anthrax Koch’s Postulates: set of rules for the assignment of a microbe as the cause of a disease (isolated the cause of anthrax, showed it to be a bacterium) •The pathogen (bacteria) must be present in all diseased individuals •Pathogen is isolated from the host with the disease and grown in a pure culture •The diseased individual must cause the disease when inoculated into a healthy, susceptible pathogen host •The pathogen must be re-isolated and shown to be the same as the originally inoculated pathogen (must recover and go back to normal when separated)Factors that decrease the infectious Diseases in the 20th Century: 1. Decrease in host susceptibility 2. Decrease in disease transmission A. Better housing B. Better nutrition C. Safer food and water D. Immunizations E. Improved Hygiene F. Antibiotics Factors Leading to the Emergence of Infectious Diseases: 1. Increase in host susceptibility 2. New diseases 3. Increase in disease transmission A. Changes in demographics and behavior B. Changes in technology and industry C. International travel and commerce D. Microbial Adaption and change E. Breakdown of public health measures F. Environmental change and land use Life Expectancy and disease: as life expectancy improves and the role of infectious, parasitic, and respiratory infections further diminish; more people survive to older ages and chronic degenerative diseases such as stroke, cancer, and heart disease will make up a large portion of
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