1. Body Defenses: Nonspecific
DESCRIBE PATHOGENS!!

2. Think, pair, share What parts of your body help you keep germs out?
Can you think of any body processes that help fight germs and disease?

3. Challenge Problem turn in the African Illness packet to the front
What is happening here?
Make an explanation the best you can.

4. Trypanosomiasis African Sleeping Sickness
1. Virus, Bacteria, Protozoan, Other?
2. How is it transmitted?
3. How does the body react to the infection?
4. Can we fight it
without drugs?
5. You cannot turn in your
packet at lunch without
using a computer. You
must turn in your own

5. Body Defenses
The body is constantly in contact with bacteria, fungi, and viruses
The body has two defense systems for foreign materials
1) Nonspecific defense system
Mechanisms protect against a variety of invaders
Responds immediately to protect body from foreign materials
Slide 12.15a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

6. Body Defenses 2) Specific defense system
Specific defense is required for each type of invader
Also known as the immune system
Slide 12.15b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

7. Quick Quiz
Explain the difference between non-specific and specific body defenses.

8. Nonspecific Body Defenses
Body surface coverings
Intact skin
Mucous membranes
Specialized human cells
Chemicals produced by the body
Slide 12.16
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

9. First Line of Defense

10. Surface Membrane Barriers
The skin
Physical barrier to foreign materials
pH of the skin is acidic to inhibit bacterial growth
Sebum (sweat) is toxic to bacteria
Vaginal secretions are very acidic
Slide 12.17a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

11. Surface Membrane Barriers
Stomach mucosa
Secretes hydrochloric acid
Has protein-digesting enzymes
Saliva and lacrimal fluid contain lysozyme
Mucus traps microogranisms in digestive and respiratory pathways
Slide 12.17b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

12. Quick Quiz
Which of the First Line of Defenses do you think is the most important any why?

13. Second Line of Defense

14. Defensive Cells Phagocytes (neutrophils and macrophages)
Engulfs foreign material into a vacuole
Enzymes from lysosomes digest the material
Slide 12.18a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 12.6b

15. Defensive Cells Natural killer cells Can lyse and kill cancer cells
Can destroy virus- infected cells
Slide 12.18b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 12.6b

16. Inflammatory Response
Triggered when body tissues are injured
Produces four cardinal signs
Redness
Heat
Swelling (from increased blood flow and white blood cells in the damaged region)
Pain
Results in a chain of events leading to protection and healing
Slide 12.19
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

17. Functions of the Inflammatory Response
Prevents spread of damaging agents
Disposes of cell debris and pathogens
Sets the stage for repair
Slide 12.20
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

18. Steps in the Inflammatory Response
Figure 12.7
Slide 12.21
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

19. Antimicrobial Chemicals
Damage foreign cell surfaces
Attract neutrophils and macrophages
Has vasodilators, chemotaxis, and opsonization
Figure 12.8
Slide 12.22b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

20. Antimicrobial Chemicals
Interferon
Proteins secreted by cells that have been infected with a virus
The proteins bind to healthy cell surfaces to inhibit viruses binding to more cells
Slide 12.22c
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

21. Fever Abnormally high body temperature
Hypothalmus heat regulation can be reset by pyrogens (secreted by white blood cells)
High temperatures inhibit the release of iron and zinc from liver and spleen needed by bacteria
Fever also increases the speed of tissue repair
Slide 12.23
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

22. Quick Quiz
When a patient has broken a bone and the area becomes inflamed, what purpose does that serve?
Why do kids have 103F temperature when they have an ear infection?

23. Non-specific Comic Strip
Create 2 comic strips modeling the
non-specific defenses against pathogens.
One will be an example of the First Line of Defense (outside)
One will be an example of the Second Line of Defense (inside)
Minimum 3 panes each, probably need more
Use color
Use captions to help with content
Pretend your grandma is coming over for dinner and she has to able to understand the cartoons.

24. Example First line of defense - -? Second line of defense
Bacteria gets on skin
No cuts, bacteria sits on skin and gets washed in sweat
Bacteria hates sweat!
Dead bacteria
Sadface bacteria, happyface human
Second line of defense
Finger gets splinter
Bacteria gets under skin
Body sends gangsta macrophages in army hats to fight bacteria
Gangsta macrophages are victorious!!