1. Your Body’s Defense

2. Physical Defenses
 First line of defense
 Skin
 Hair
 Mucous
 Cilia
 Saliva
 Tears
 Sweat
 Digestive tract

3. Skin
 Protects from micro-organisms entering
the body
 Open cuts/ sores provide entrance
 Cells die and are shed

4. Sweat
 Our body has many sweat glands
 Sweat is released to control body temp
 Sweat contains acids that kill pathogens

5. Mucous Membranes
 Moist linings around all
entrances to body
 Covered with mucous
 Mucous = sticky
substance
 Mucous traps
pathogens
 Mucous is released
from body

6. Saliva & Tears
 Contain enzymes
that fight
pathogens
 Tears wash away
foreign
substances

7. Cilia
 Tiny hair-like structures
 Trap pathogens
 Help remove mucous from body

8. Digestive Tract
 Moves pathogens
out of body
 Acids/ chemicals in
digestive tract
 Stomach/ intestines/
bladder
 Chemicals kill
pathogens

9. Second Line of Defense
 Occurs after pathogen enters the body
 Inflammation

10. Inflammation
 1st
stage of healing
 Increased blood flow to area
 Increased size/ temperature/ redness
 Caused by dilation of blood vessels

11. Phagocytes
 Blood brings
phagocytes & chemicals
 Phagocytes = white
blood cells
 Digest pathogens,
dead cells, waste
 Chemicals
 Kill pathogens & start
tissue healing

12. Immune System
 Last line of defense
 Lymphatic system,
lymph nodes, lymph,
lymphocytes
 Lymph nodes store
and filter lymph
 Lymph - fluid
containing
lymphocytes
 Lymphocytes - white
blood cells

13. Lymphocytes
 B-cells & T-cells
 T-cells
 Produce interferon- warns
cells about pathogen
 Kill some pathogens directly
 B-cells create antibodies
 Antibodies bind to
pathogens/ toxins until
phagocytes find them

14. Immunity
 Active Immunity-body
creates antibodies
 Through sickness of
immunization
 Immunization/ vaccine –
injected with small amount
of pathogen
 Passive Immunity-passed
from mother to child
through birth or breast milk

15. Treatment
 Antibiotics – kill living organisms
 Treat bacterial infections only
 Fungus are treated with cream or topical
treatment

16. Treatment of Virus
 Anti-viral can stop a virus from
reproducing
 Most viruses are fought by our immune
system with…
 Rest
 Proper diet
 Water

17. Prevention
 Eat well-balanced meals.
 Get enough rest. (8 hours)
 Get exercise. (30 minutes at least 3-4 x
week)
 Wash hands/ shower.
 Keep hands out of eyes and mouth.
 Have regular physicals/ dental visits.

18. Prevention
 Get vaccinated
 Don’t share utensils,
glasses, cups etc.
 Avoid sick people.
 Avoid stress. Use stress
management techniques.
 Find time to relax.

19. Questions