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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1st 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:
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Physical Barriers:
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Chemical Barriers:
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2nd line of defence: When the pathogens get past the 1st line of defence the 2nd
line of defence takes over which consists 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 3rd 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 infected by the same pathogen again.
What are the two main components of the immune response and what are their
function?
T-Lymphocytes (T-cells)
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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
pathogens, 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 pathogen.
The antibodies travel through the _______________ and work as tags binding to the
pathogens stopping the pathogens from binding to healthy tissues or
immobilising them for ________________ 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