Transcript Aim – How does my body fight illness?

Aim – How does my body fight
illnesses?
Do Now
How might
disease
organisms
spread to a
person in
this setting?

Aim – How does my body fight illness?
What causes disease ?
Where do infectious diseases come
from?
 PATHOGENS!!!!!!
 Pathogens are bacteria, viruses, or
protists
 Not all microorganisms are pathogens
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Aim – How does my body fight illness?
Aim – How does my body fight illness?
Aim – How does my body fight illness?
Aim – How does my body fight illness?
Transmission or Spread of
Disease
How do the pathogens infect humans?
 Through
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 Direct contact -Objects – pathogens living
on non living things
 Indirect- coughing or sneezing into the air
 Vectors – mostly through arthropods (like
insects)
Aim – How does my body fight illness?
Sick?

Being sick is when you have some sort
of infectious disease
 Ex- Cold
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Also this infectious disease causes
something called an immune response
Aim – How does my body fight illness?
Immune response
What is the immune response?
 Your body tries to kill the pathogens and
cure you
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 Includes fevers, rushing blood to affected
areas, stomach acid etc.
How does this happen??
 White blood cells are important
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Aim – How does my body fight illness?
Why?
Why do we need the immune system?
 To protect us and keep us healthy
 Without it we would die easily
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Aim – How does my body fight illness?
How?
How does the immune system protect
us?
 Our first line of defense is our skin- a
great barrier .
 Chemical Defense- saliva, tears, mucus
and stomach acid helps to kill
pathogens.
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What happens when you get a splinter?
 The area becomes red, warm and
inflamed(swollen)
 Cells called phagocytes rush to the area
and eat the bacteria
 Fever-another defense for the body
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White Blood Cells
Aim – How does my body fight illness?
White blood cells
Some white blood cells “eat” pathogens
 Others label pathogens as bad
 Some kill pathogens
 Some kill infected cells
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Aim – How does my body fight illness?
How are invaders recognized?

Antigens (Antibody-generator)
 chemical name tags on the surface of
every cell
○ “self” vs. “invader”
one of your
own cells
disease-causing
virus
disease-causing
bacteria
antigens say:
“I belong here”
antigens say:
“I am an invader”
antigens say:
“I am an invader”
Aim – How does my body fight illness?
Antibiotics
Antibiotics are medicines that kill
bacteria only, not viruses
 Should only be used with bacterial
infections
 Some bacteria are resistant against
antibiotics
 Overuse of antibiotics can create
resistant strains resistant
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Regents Question
Antibiotics are substances used to help fight an
infection of Streptococcus, a bacterium that
causes strep throat. Overuse of these antibiotics
can
(1) prevent future infections by these pathogens
(2) cause a decrease in the production of
enzymes
(3) allow organic molecules to be synthesized
(4) select for resistant organisms
Regents question
Cells of the immune system are able to
respond to the presence of invading
organisms because they recognize the
(1) antigens present on the invaders
(2) antibodies present in invading
pathogens
(3) DNA pattern in the nuclei of viruses
(4) antibiotics released from microbes