Transcript The Immune System

The Immune System
Disease Transmission
Robert Koch…”father of disease,” came up
with first procedure for identifying the
pathogens responsible for a disease.
-Worked with anthrax
-Koch’s Postulates – “rules” for determining
the cause of the disease
Human Diseases and How They
Are Transmitted
AIDS
HIV
Intercourse,
contaminated syringes
Common Cold
many viruses
air, person to person
Malaria
protozoan parasites
mosquitoes
Measles
paramyxovirus
air, person to person
Botulism
Clostridium botulinum
contaminated food
Invaders to the Body
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Pathogens – foreign particles
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Ex. Viruses + bacteria
Multiply in the body to cause infection
 Come into contact with the body by:
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Air
Food
Water
Person-to-person contact
Animal bites
NonSpecific Defenses...First
Line of Defense
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Skin – prevents entry
Oil – traps and kills invaders
Mucous/tears/saliva – wash, trap, and kill
• Mucous/saliva – swallowed; stomach acid kills
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Ear wax – traps
Hair/Cilia - traps
NonSpecific Defenses...Second
Line of Defense
If a pathogen penetrates the first line of
defense...
1. Inflammatory Response:
-Histamine released (Increases blood flow to site of
injury/infection; can cause redness, swelling, warmth,
and pain)
-White Blood Cells (Phagocytes)
• Attack/ingest foreign particles
• Neutrophils & Macrophages
• Natural Killer Cells
2. Interferon
• protein that inhibits reproduction of viruses
3. Fever
• sign body is responding to infection
• suppresses growth and reproduction
• promotes action of white blood cells
Specific Defenses...The Immune System
1. Bone Marrow
-Produces white blood cells (lymphocytes)
-Two types: B cells & T cells (thymus)
2. Thymus
-Place of maturation of white blood cells
3. Lymph & Lymph Nodes
-Filter pathogens, lymphocytes
4. Spleen
-Filters pathogens from blood
5.
Tonsils & Adenoids
-Contain lymphocytes which are important for
antibody production.
The Immune Response..two
pronged attack!
Begins with ‘Recognition’ of an Antigen
(pathogen).
-differing response based upon surface
proteins on the antigen.
1. Cell-Mediated
2. Humoral
1. Cell-Mediated Immune Response
-T cells (cytotoxic & suppressor)
-destroy infected cells
-shut down response after pathogens are cleared
2. Humoral Immune Response
-B cells change into plasma cells and produce
antibodies.
Antibodies – chemicals that binds to antigen to
disable the pathogen (block reproduction).
-Antigen specific
-Stores antibodies for the future use
Primary Immune Response
-first time the body encounters an
antigen.
Secondary Immune Response
-Response of memory cells to an
infection by a former pathogen.
Additional Specific Defenses
 Immunity
(survival or vaccination)
 Allergies
 Autoimmune
Diseases- immune system
attacks your own body cells. (MS,
type I diabetes, rheumatoid arthritis)
AIDS
AIDS is a disease in which the immune
system loses its ability to fight off
pathogens and cancers.
Caused by the HIV virus
Transmitted by the transfer of body fluids &
needles.