Transcript The Human Immune System

The Human Immune System
Immunology and Disease
Basic Definitions
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Disease:
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Types of diseases
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Hereditary
Materials in Environment
Pathogen induced
Pathogens:
Infectious Disease:
Vector:
Examples of Vector-Bourne Diseases
A Case study
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See Overhead
Questions:
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What is the cause of the disease?
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Heredity, Chemicals, pathogen
What specific steps would you take to determine
the exact cause of the disease?
Immunology History
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For thousands of years people believed that
diseases were caused by the devil and medicinal
techniques would rely upon spiritual cures
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1800’s – Germ Theory of Disease
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Examples:
Definition:
Who was responsible?
Question still existed:
How do you identify the specific pathogen?
Koch’s Postulates – The Guideline
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Pathogen should only be found in a sick
organism
Isolate the pathogen from the sick organism
and grow it in a pure culture
Koch’s Postulates – Take 2
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Place purified pathogen in new host and
compare symptoms
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Re-isolate the pathogen and make sure it is
identical to the original
Miscellaneous Topics
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Why is the human body so perfect for infection?
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3 Reasons
Normal Flora
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Definition:
Example
The Immune System
The Immune System
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2 types of responses to an invading pathogen
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Non-specific Defenses:
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Specific Defenses:
Which type of response occurs first?
Progression of a pathogen in the body:
Breach the outer surface
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What makes the skin so difficult to
breach?
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Function:
Mechanism:
Specific or Non-specific defense?
What if the pathogen attacks thru the
mouth, nose or throat?
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Mucus and lysozymes
Progression of a pathogen in the body:
The Inflammatory Response
Histamine
Increase Blood Flow
Histamine
White Blood cells attack
pathogen
Veins swell and
release blood and
WBC’s into
infected area
The Inflammatory Response
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Responds to a local infection
Damaged cells release histamine
Blood flow near the wound increases
Blood vessels swell and release phagocytes
into surrounding area
Additional white blood cells are made and
drawn towards the wound
Progression of a pathogen in the body:
The Inflammatory Response
Histamine
Increase Blood Flow
Histamine
White Blood cells attack
pathogen
Veins swell and
release blood and
WBC’s into
infected area
Progression of a pathogen in the body
FEVER
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Definition:
Why would you raise your body temperature?
(3 Reasons)
What is Interferon?
The Immune System:
Progression of a pathogen in the body
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What if fever does not work?
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Specific Defenses
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Background: Every pathogen has an antigen
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The antigen triggers the immune response
Humoral Response
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Definition:
Key Players:
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B-Lymphocytes (B-cells)
T-Lymphocytes (T-cells)
Plasma cells
Antibodies
Phagocyte
The pathogen (Booo!)
Humoral Response
THE PATHOGEN!!!
HISS!!!
BOOO!
Antigen
BOOOO!
Blood vessel
Humoral Response
1000’s of B-Cells
WE’RE
SAVED!!!
YEAH!!!
MY HERO!
Humoral Response
One Right B-Cell that
recognizes the antigen
MACHO MACHO MAN
I GOT TO BE A MACHO MAN
Humoral Response
T-Cell Helps to
activate the B-Cell
P
Plasma Cell
Humoral Response
B-cell makes
specific antibody
S
Y
Humoral Response
Antibody grabs 2 pathogens
Help Me!
Y
Humoral Response
Phagocyte engulfs and
destroys both pathogens
and the antibody
T
A review of Humoral Response
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A B-cell recognizes the pathogen’s antigen
The B-cell is activated by the T-cell and
becomes a plasma cell
The plasma cell makes antibodies
The antibodies capture the pathogen and
cluster together
Phagocyte destroys the entire complex
(antibodies and pathogens)
Humoral Response
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It’s better to be prepared
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Memory:
Humoral Immunity Review Website
http://bcs.whfreeman.com/thelifewire/content/chp18/1802004.html
CELL MEDIATED RESPONSE
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If the pathogen begins to infect cells
Immune system must destroy the infected
cells or the entire organism will die
Key Players
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Macrophage
T-cells (Killer T-cells)
Pathogen (Booo!)
CELL MEDIATED RESPONSE
THE PATHOGEN
Antigen
CELL MEDIATED RESPONSE
Macrophage
A Large WBC
(Macrophage) Engulfs
a Pathogen
CELL MEDIATED RESPONSE
Learned Antigen
Macrophage
learns antigen of
pathogen and
displays it on its
membrane
CELL MEDIATED RESPONSE
T-Cell Binds to
macrophage and
learns the antigen
and in doing so
BECOMES…
CELL MEDIATED RESPONSE
Well, actually only a killer t-cell
CELL MEDIATED RESPONSE
Killer T-cell recognizes the
infected cell, binds to the cell
and destroys the cell!
Infected Cell
CELL MEDIATED RESPONSE
YEAH, WE’RE SAVED
CELL MEDIATED RESPONSE
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Macrophage engulfs the pathogen and
displays the antigen for a T-cell
T-cell learns pathogen and hunts out infected
cells
Once found, T-cells destroy infected cells
(thru a process known as apoptosis)
Cell mediated response
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Importance of T-cells in immune system?
 Cell Mediated Response Review Website
http://bcs.whfreeman.com/thelifewire/content/chp18/1802003.html
Types of Immunity
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Permanent Immunity
Critical time when
sickness becomes
symptomatic
Number of
pathogens
Duration of Sickness
Types of Immunity
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Active Immunity (Vaccination)
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Definition
Who invented the 1st vaccine?
Immunity is permanent to that
specific type of pathogen
Question: Why must we get
multiple vaccines during our
lives?
Types of Immunity
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Passive Immunity
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Definition:
Provides temporary immunity
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WHY???
Why would you get this type of immunity?