The Immune System
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Transcript The Immune System
The Immune System
Protects against foreign cells and viruses
1st Line of Defense
Skin = Barrier Defense
Mucus (respiratory tract) = traps
pathogens
Sweat, Tears, Saliva
contains enzymes that digest cell walls
Decrease pH of skin
2nd Line of Defense
Non specific cellular defense
Macrophages!
Eat
cellular debris and pathogens
Release interleukins to summon reinforcements
(helper T cells)
Achy
Fever
NOM NOM!
Inflammation
Histamine released by injured cells
Increases permeability of capillaries (tiny
blood vessels at tissues) to allow for more
macrophages in the area
Interferon: neighborhood warning protein
released by infected cells
3rd Line of Defense
Specific Immunity
Cells triggered by helper T cells
T cells: destroy infected cells with “surgical
precision”
B cells: make antibodies that paralyze viruses
Memory cells: patrol body for rest of life
Active vs. passive immunity
Active immunity goes through all of the
steps and leads to development of
memory cells
Normal immune response
Vaccinations
Passive immunity gives temporary
immunity via antibodies not produced by
individual
Fetus, breastfeeding
Snake bite anti-venom
HIV
Virus that infects T cells
Disables defense system
Antibody Actions