First Line of Defense

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First Line of Defense
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What if the first line of defense lets a pathogen
by?? A macrophage (above with streptococcus),
begins the second line of defense.
Second Line of Defense
A macrophage is the biggest white blood cell in
the body
A macrophage recognizes a pathogen by its marker
proteins The macrophages surrounds and eats the
pathogens . Then it places a piece of it on its
outer membrane (a victory banner)
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• 3rd Line of Defense
• Helper-T Cells are the cheerleaders for the
  immune system
• Become activated by macrophages

• The T-cells communicate two things
• Tell B-cells to make antibodies
• Tell Killer T-cells begin dividing.

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Antibodies recognize foreign antigens and mark
them for destruction by macrophages and killer
T-cells
Antibodies are made to mark only a certain kind
of pathogen.
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Killer T-cells look for infected cells and kill
them.
They will also kill any pathogens that have
antibodies surrounding them
These killer T-cells recognize and kill the same
pathogens that the macrophage killed earlier.
(The Killer T- cell is marked by the arrow. It is
killing a much larger influenza virus infected
target)
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The Suppressor T-cell tells the B-cells when the
body can stop making antibodies.
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T-cells B-cells leave behind memory cells that
watch for the pathogen.
If they find one, they start multiplying to kill
it.
This process is so immediate explosive that the
pathogen is killed before you know you are sick.
You are immune to that pathogen
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Second Introduction
First Introduction
Time
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3 Types of T-Cells
Macro- phages
B-Cells Antibodies
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Allergies an abnormal response to a pathogen
(pollen, dust, pets etc.) Immune system is
super-sensitive to the pathogen and initiates the
first line of defense.
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Viruses are made up of a protein coat and RNA or
DNA It is debated whether viruses are living or
non-living things since they cannot reproduce on
their own.
Viruses inject their DNA/RNA into our cells and
our cells produce the viruses. After the cell
produces the viruses the cell dies.
To combat a virus we use vaccines. Vaccines help
our body to produce memory cells
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Some viruses like HIV are called retro viruses
they contain RNA instead of DNA
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Bacteria are living things (Monera)
Bacteria can help us do many good things make
yogurt, treat water, clean oil spills etc.
Antibiotics kill bacteria by damaging their cell
wall
This doesnt affect our cells
because they do not have cell walls