1. The Immune System

2. 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.

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

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

8. Bacteria don’t grow around mold!!!

9. History of Medicine 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 1994.
Today
Polio Comeback!
Worldwide efforts increase to vaccinate people against polio.
Antibiotics
Sir Alexander Fleming discovers penicillin.
Germ Theory
Louis Pasteur hypothesizes that disease is caused by small organisms.

10. The Skin 1st line of defense: physical barrier
Oils & sweat destroy some pathogens
Some cells burst
Some cells shrivel

11. Mucus Membranes Coat the openings of the body
Nose, mouth, ears, eyes, genitals, anus
Lined with cilia & sticky fluids to trap pathogens

12. White Blood Cells Job: Search & destroy
Phagocytes: surround & engulf invaders
Phagocytosis (see animation)
Lymphocytes:
T cells: destroy infected body cells
B cells: Inactivate invaders

13. phagocyte
bacteria
phagocyte

17. Defense Proteins Antibodies Proteins made by B cells
How can they help:
1. Bind to antigens of pathogen (like handcuffs)
Causes pathogens to clump
Easy targets for phagocytes
2. Weakens the cell membrane
Causes them to burst

19. Defense Proteins Interferon
virus
Interferon
Infected cell (left) produces and releases interferon
Uninfected cell (right) absorbs the interferon and creates enzymes to fight the pathogen
Virus RNA
New virus
New virus
New virus
New virus
Interferon
proteins
New virus

20. Vaccination Prevents infections (not a cure) Vaccination process
Weakened pathogen is injected
Antigens on pathogen
Immune response:
Production of memory cells (future infections)
Antibodies bind to antigens (current infection)
Goal: Speed up immune response if you encounter the unweakened virus

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

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

25. 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

27. 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)

29. 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

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

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