Transcript First line of defense - CGW-Life-Science

Infectious Disease The Body’s Defenses
It’s like The Three Little Pigs…
Enemy
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1st defense
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2nd defense
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3rd defense
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When we look at our body’s defense…
Pathogens
1st defense
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2nd defense
3rd defense
In the first line of defense, the
surfaces of the skin, breathing
passages, mouth and stomach
function as barriers to pathogens.
The barriers trap and kill most
pathogens.
First line of defense - SKIN
Pathogens are exposed to destructive
chemicals in oil and sweat. If that
doesn’t get them, the pathogens may fall
off with dead skin cells. If THAT doesn’t
get them, they have to get through the
tightly packed dead skin cells on top of
living skin cells. Most pathogens can
only get through when the skin is cut.
First line of defense - BREATHING PASSAGES
Pathogens are trapped in the mucus and
cilia that line your nose, pharynx, trachi
and bronchi. Plus, pathogens are
irritating and make you sneeze or cough.
First line of defense - Mouth and Stomach
The saliva in your mouth contains
destructive chemicals and your stomach
produces acid.
When we look at our body’s defense…
Pathogens
1st defense
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2nd defense
3rd defense
In the first line of defense, the
surfaces of the skin, breathing
passages, mouth and stomach
function as barriers to pathogens.
The barriers trap and kill most
pathogens.
Example summary - Cornell Notes
First line of defense (words to use: skin, breathing
passages, mouth and stomach)
The body has a first line of defense that’s like a straw
fence. Skin provides a barrier that prevents
pathogens from getting inside the body. Breathing
passages are lined with cilia and mucus that trap
pathogens. Pathogens are irritating and sometimes
you sneeze or cough to send the pathogens out of
your body. Gross. The saliva in your mouth and the
acid in your stomach also kills pathogens.
When we look at our body’s defense…
Pathogens
1st defense
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2nd defense
3rd defense
Sometimes pathogens make it
inside your body and begin to
damage cells. In the second line
of defense, damaged body cells
release chemicals that trigger the
inflammatory response.
Second line of defense - Inflammatory Response
In the inflammatory response, fluid and
white blood cells leak from blood vessels
into nearby tissues. The white blood cells
then fight the pathogens.
Second line of defense - Inflammatory Response
White Blood Cells
All white blood cells are disease fighters.
White blood cells involved in
inflammatory response are phagocytes.
Second line of defense - Inflammatory Response
Inflammation
During the inflammatory response,
blood vessels widen in the areas
affected by the pathogens. This
enlargement increases blood flow
(more white blood cells).
Second line of defense - Inflammatory Response
Fever
In some cases, chemicals produced
during the inflammatory response cause
a fever. Some pathogens do not grow
and produce well at higher temperatures.
When we look at our body’s defense…
Pathogens
1st defense
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decompressor
are needed to see this picture.
2nd defense
3rd defense
Sometimes pathogens make it
inside your body and begin to
damage cells. In the second line
of defense, damaged body cells
release chemicals that trigger the
inflammatory response.
When we look at our body’s defense…
Pathogens
1st defense
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2nd defense
3rd defense
If a pathogen infection is severe
enough to cause a fever, it
triggers the immune response.
The cells of the immune system
react to each kind of pathogen
with a defense custom-made for
that pathogen.
Third line of defense - Immune Response
The two types of white blood cells that distinguish between different kinds
of pathogens are called T Cells and B Cells.
T Cells
T Cells look for specific antigens on each pathogen.
B Cells
B Cells produce proteins called antibodies that help
destroy pathogens.
When antibodies bind to the antigens on a pathogen, they
mark the pathogen for destruction.
The Immune Response
Antigen
Pathogen
Some T cells
attack infected
cells and
pathogens
T Cell
T cell recognizes
antigens on
pathogen and divides
over and over again
T Cell
B Cell
Other T cells signal B
cells to make
antibodies against the
pathogen’s antigens
The Immune Response
B Cell
B cells makes
antibodies to fight the
pathogen’s antigens
Antibodies
Antigen
Antibodies bind to the
antigens.
Pathogen
The pathogens clump together
and are destroyed by
phagocytes.
Phagocyte
www.phschool.com
Cep-4052
It’s one giant fairytale AGAIN…
Enemy
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Pathogen
1st defense
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Barriers
Chemicals
2nd defense
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Inflammation
3rd defense
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Immune
System