History of Medicine Today Germ Theory Louis Pasteur hypothesizes that disease is caused by small organisms.

History of Medicine Today Germ Theory Louis Pasteur hypothesizes that disease is caused by small organisms. Koch’s Postulates Robert Koch finds 4 conditions that prove a pathogen causes a disease.

History of Medicine Today Germ Theory Louis Pasteur hypothesizes that disease is caused by small organisms. Koch’s Postulates Robert Koch finds 4 conditions that prove a pathogen causes a disease. Antibiotics Sir Alexander Fleming discovers penicillin.

Bacteria don’t grow around mold!!!

History of Medicine Today Germ Theory Louis Pasteur hypothesizes that disease is caused by small organisms. Koch’s Postulates Robert Koch finds 4 conditions that prove a pathogen causes a disease. Polio Vaccine Jonas Salk’s vaccine against polio becomes available. Discontinued in the U.S. in Antibiotics Sir Alexander Fleming discovers penicillin. Polio Comeback! Worldwide efforts increase to vaccinate people against polio.

 1 st line of defense: physical barrier  Oils & sweat destroy some pathogens Some cells burst Some cells shrivel

 Coat the openings of the body  Nose, mouth, ears, eyes, genitals, anus  Lined with cilia & sticky fluids to trap pathogens

 Job: Search & destroy  Phagocytes: surround & engulf invaders Phagocytosis (see animation)  Lymphocytes: T cells: destroy infected body cells B cells: Inactivate invaders

 Complimentary Proteins Weaken cell membrane Attract phagocytes Cause microbes to stick to wall of blood vessel

 Antibodies Made by B cells Bind to cell membrane of pathogen Prevents pathogen from binding to host cells Causes pathogens to clump  More susceptible to phagocytes Weakens the cell membrane  Causes them to burst

 Interferon Produced by virus infected cells Stimulates uninfected cells to create infection preventing enzymes

 Prevents infections (not a cure)  Memory cells developed without actually getting the disease  Vaccine Contains antigens of a pathogen Weakened pathogen is injected Stimulates the production of memory cells  Speeds up immune response if you encounter the unweakened virus

Pathogens  Defined: microorganisms that cause disease Viruses: turn cells into virus making factories

 Defined: microorganisms that cause disease Viruses: turn cells into virus making factories Bacteria: prokaryotes that can release toxic chemicals

Pathogens  Defined: microorganisms that cause disease Viruses: turn cells into virus making factories Bacteria: prokaryotes that can release toxic chemicals Fungi: pierce cells and absorb the nutrients

Pathogens  Defined: microorganisms that cause disease Viruses: turn cells into virus making factories Bacteria: prokaryotes that can release toxic chemicals Fungi: pierce cells and absorb the nutrients Protozoans: single cells protista (eukaryotes)

Pathogens  Defined: microorganisms that cause disease Viruses: turn cells into virus making factories Bacteria: prokaryotes that can release toxic chemicals Fungi: pierce cells and absorb the nutrients Protozoans: single cells protista (eukaryotes) Parasites: grow and feed on a host

 Some carried by wind, water, direct contact, indirect contact…  Some carried by vectors Vector: object that carries a pathogen Examples: 1) Malaria – mosquitos carry the protozoan 2) Black Death – carried by flea’s of mice 3) West Nile Virus – carried by birds, but spread by mosquitos

1) What did Louis Pasteur contribute to our knowledge of medicine? 2) Which part of our immune system coats the openings of the body? 3) Name and describe the two types of lymphocytes. 4) What are antibodies and how do they help keep us from harm? 5) Summarize how vaccines are created. 6) Which pathogen… 1)absorbs nutrients from living tissue? 2)is prokaryotic? 7) Which illness is spread by mice? 8) What is the vector of malaria?