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BIOLOGY 111
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CHAPTER 29: Defending the Body
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The Immune System
Defending the Body: The Immune System
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29.x Preventing an Immune Response
29.1 The Immune System in Overview
29.2 The Innate Immune Response
29.3 The Adaptive Immune Response
29.4 Inducing Immunity: Vaccination
29.5 The Immune· System Can Cause Trouble
ESSAYS
 Why Is There No Vaccine for AIDS?
 Unfounded Fears about Vaccination
Defending the Body: The Immune System
The Digestive and Respiratory Systems
connect to the Cardiovascular System –
allowing entry of materials and access
to our entire body. (Good or Bad!)
We have multiple lines of defense that
either keep pathogens out of our body,
or eliminate them if they gain access to
our body.
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Preventative Defenses
Immune Response
Defending the Body: Before the Immune System
Preventative Defenses: Barriers to Infection
Skin:
Mucous Membranes:
Defending the Body: Before the Immune System
Preventative Defenses: Barriers to Infection
Skin: (waterproof)
Keratin
Sweat
Sebum
Normal Flora
Defending the Body: Before the Immune System
Preventative Defenses: Barriers to Infection
Skin: (waterproof)
Keratin (waxy substance covering skin cells)
Sweat (salt and low pH 3 to 5)
Sebum (fatty oily substance on skin)
Normal Flora (Staphylococcus, Pseudomonas)
Commensal bacteria suppress growth of
pathogenic bacteria by taking up available
space and nutrients. Pseudomonas produce
antimicrobial substances (pseudomonic acid).
Defending the Body: Before the Immune System
Preventative Defenses: Barriers to Infection
Mucous Membranes:
Mucous (physically traps microbes)
Cilia (move mucous – and trapped microbes – out of the body
Defending the Body: The Immune System
•
•
•
•
•
•
•
29.x Preventing an Immune Response
29.1 The Immune System in Overview
29.2 The Innate Immune Response
29.3 The Adaptive Immune Response
29.4 Inducing Immunity: Vaccination
29.5 The Immune· System Can Cause Trouble
ESSAYS
 Why Is There No Vaccine for AIDS?
 Unfounded Fears about Vaccination
Defending the Body: The Immune System
The Digestive and Respiratory Systems
connect to the Cardiovascular System –
allowing entry of materials and access
to our entire body. (Good or Bad!)
We have multiple lines of defense that
either keep pathogens out of our body,
or eliminate them if they gain access to
our body.


Preventative Defenses
Immune Response
The Immune System in Overview: THE INVADERS!
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Toxins, that someone might ingest, or carcinogens, such as
asbestos, are usually removed from the body through the liver and
kidneys.
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Microorganisms that enter or invade the body are addressed by
components of the immune system.
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Antigen = Any substance that provokes an immune response
What is an immune response?
The Immune System in Details
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All Microbes (bacteria, viruses,
protozoans) have unique proteins
and carbohydrates on their surface
The Immune System in Details
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All Microbes (bacteria, viruses,
protozoans) have unique proteins
and carbohydrates on their surface
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These proteins and carbohydrates
are recognized as foreign by
immune system cells - when this
happens an immune system attack
will follow.
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Any substance that elicits an immune system attack is an antigen.
The Immune System in Overview
What is an immune response?
An Immune Response is how our body identifies specific
invaders and then responds to neutralize them.
The Immune System in Overview
Proteins of the Immune System:
Complement Proteins:
• Assist with immune response
Antibodies:
• Specific antigen receptors
• On cell surface or ‘free’
Cytokines:
• Signaling Proteins – often a
signal for inflammation
The Immune System in Overview
Cells of the Immune System:
Macrophages
 Phagocytes (ingest other cells)
 Antigen Presenters
Mast Cells
 Release Histamine
B-Lymphocytes
 Antibody Responses
T-Lymphocytes
 Kill virally infected cells
The Immune System in Overview
Cells of the Immune System
Macrophages
 Phagocytes (ingest other cells)
 Antigen Presenters
Mast Cells
 Release Histamine
B-Lymphocytes
 Antibody Responses
T-Lymphocytes
 Kill virally infected cells
The Immune System in Overview
Pathways of the Immune System:
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Innate immune response: A response that is triggered by an
apparent pathogen (antigen) but does not target specific invaders.
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Adaptive immune response: A response that is triggered by an
apparent pathogen (antigen) and targets specific invaders.
This System has a ‘memory’ long-term function