Immune System: The 3 lines of defence
Watch:
https://www.youtube.com/watch?v=PzunOgYHeyg
and answer the questions
What is the purpose of the immune system?
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What is
the non
specific immune system?
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1
st
Line of Defence:
The first line of defence consists of
physical
and
chemical
Barriers. Write down the
different examples of physical and chemical barriers and
their specific
functions
:

Physical Barriers:
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Chemical Barriers:
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2
nd
line of defence
:
When the pathogens
get
past the 1
st
line of defence the 2
nd
line of defence takes over which c
onsists of
an
inflammatory response involving
white blood cells
that fight the pathogens
.
How is an inflammatory response
made and how does it aid your immune
system?
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What are the roles of the different phagocytes (type of white blood
cell) in the
innate system?
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Neutrophils:
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Macrophages:
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Natural Killer Cells:
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The 3
rd
line of defence
is a immune response that
is designed to go after
specific targets
and keeps information on each pathogen so it knows how to
fight it when
you are infec
ted by
the same pathogen again.
What are the two main components of the immune response and what
are their
function?
T
Lymphocytes (T
cells)

Helper T
cells (Effector and Memory):
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Cytotoxic T
cells:
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B
Lymphocytes (B
cells)
B
cells produce
proteins
called
________________.
They lock
onto sites on
pathogen
s
, called
________________,
just like a lock and key.
When the
B
cells with
antibodies
recognise and bind to an antigen of a
________________
it replicates and
produces numerous antibodies to target the specific antigen on the
path
ogen.
The antibodies travel through the
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and work as tags binding to the
pathogens stopping the pathogens from binding to healthy tissues or
immobilising them for
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to swallow them up. Just like T
cells, B
-
cells
have
_________
_____
cells
that keep a record of each infection from pathogens to
strengthen and solidify the body’s ___________ response to the
infections in the
future.
Word bank:
memory,
antibodies, blood, antigens,
immune
,
macrophages,
pathogen