The Immune SystemThe Immune System

Disease TransmissionDisease Transmission

Robert Koch…”father of disease,” came up Robert Koch…”father of disease,” came up with first procedure for identifying the with first procedure for identifying the pathogens responsible for a disease.pathogens responsible for a disease.

-Worked with anthrax-Worked with anthrax

-Koch’s Postulates – “rules” for determining -Koch’s Postulates – “rules” for determining the cause of the disease the cause of the disease

Human Diseases and How They Human Diseases and How They Are TransmittedAre Transmitted

AIDSAIDS HIVHIV Intercourse, Intercourse, contaminated contaminated

syringessyringes

Common ColdCommon Cold many virusesmany viruses air, person to air, person to personperson

MalariaMalaria protozoan parasitesprotozoan parasites mosquitoesmosquitoes

MeaslesMeasles paramyxovirusparamyxovirus air, person to personair, person to person

BotulismBotulism Clostridium botulinumClostridium botulinum contaminated foodcontaminated food

Invaders to the BodyInvaders to the Body

Pathogens – foreign particlesPathogens – foreign particles Ex. Viruses + bacteriaEx. Viruses + bacteria

Multiply in the body to cause infectionMultiply in the body to cause infection Come into contact with the body by:Come into contact with the body by:

AirAir FoodFood WaterWater Person-to-person contactPerson-to-person contact Animal bitesAnimal bites

NonSpecific Defenses...First NonSpecific Defenses...First Line of DefenseLine of Defense

Skin – prevents entrySkin – prevents entry Oil – traps and kills invadersOil – traps and kills invaders Mucous/tears/saliva – wash, trap, and killMucous/tears/saliva – wash, trap, and kill

• Mucous/saliva – swallowed; stomach acid killsMucous/saliva – swallowed; stomach acid kills Ear wax – trapsEar wax – traps Hair/Cilia - trapsHair/Cilia - traps

NonSpecific Defenses...Second NonSpecific Defenses...Second Line of DefenseLine of Defense

If a pathogen penetrates the first line of If a pathogen penetrates the first line of defense...defense...

1. Inflammatory Response:1. Inflammatory Response:

-Histamine released (Increases blood flow to site of -Histamine released (Increases blood flow to site of injury/infection; can cause redness, swelling, injury/infection; can cause redness, swelling, warmth, and pain)warmth, and pain)

--White Blood Cells (Phagocytes)White Blood Cells (Phagocytes)• Attack/ingest foreign particlesAttack/ingest foreign particles• Neutrophils & Macrophages Neutrophils & Macrophages • Natural Killer CellsNatural Killer Cells

22. . InterferonInterferon• protein that inhibits reproduction of virusesprotein that inhibits reproduction of viruses

3. Fever3. Fever• sign body is responding to infectionsign body is responding to infection• suppresses growth and reproductionsuppresses growth and reproduction• promotes action of white blood cellspromotes action of white blood cells

Specific Defenses...The Immune Specific Defenses...The Immune SystemSystem

1. Bone Marrow1. Bone Marrow

-Produces white blood cells (lymphocytes)-Produces white blood cells (lymphocytes)

-Two types: B cells & T cells (thymus)-Two types: B cells & T cells (thymus)

2. Thymus2. Thymus

-Place of maturation of white blood cells-Place of maturation of white blood cells

3. Lymph & Lymph Nodes3. Lymph & Lymph Nodes

-Filter pathogens, lymphocytes-Filter pathogens, lymphocytes

4. Spleen4. Spleen

-Filters pathogens from blood-Filters pathogens from blood

5.5. Tonsils & AdenoidsTonsils & Adenoids

-Contain lymphocytes which are important for -Contain lymphocytes which are important for antibody production.antibody production.

The Immune ResponseThe Immune Response..two ..two pronged attack!pronged attack!

Begins with ‘Recognition’ of an Begins with ‘Recognition’ of an AntigenAntigen (pathogen).(pathogen).

-differing response based upon -differing response based upon surface proteins on the antigen.surface proteins on the antigen.

1. Cell-Mediated1. Cell-Mediated2. Humoral2. Humoral

1. Cell-Mediated Immune Response1. Cell-Mediated Immune Response-T cells (cytotoxic & suppressor)-T cells (cytotoxic & suppressor)-destroy infected cells-destroy infected cells-shut down response after pathogens are cleared-shut down response after pathogens are cleared

2. Humoral Immune Response2. Humoral Immune Response-B cells change into plasma cells and produce -B cells change into plasma cells and produce

antibodiesantibodies..

Antibodies – chemicals that binds to antigen to disable Antibodies – chemicals that binds to antigen to disable the pathogen (block reproduction).the pathogen (block reproduction).

-Antigen specific-Antigen specific-Stores antibodies for the future use-Stores antibodies for the future use

Primary Immune ResponsePrimary Immune Response

-first time the body encounters an -first time the body encounters an antigen.antigen.

Secondary Immune ResponseSecondary Immune Response

-Response of memory cells to an -Response of memory cells to an infection by a former pathogen.infection by a former pathogen.

Additional Specific DefensesAdditional Specific Defenses

Immunity (survival or vaccination)Immunity (survival or vaccination) AllergiesAllergies Autoimmune Diseases- immune system Autoimmune Diseases- immune system

attacks your own body cells. (MS,attacks your own body cells. (MS,

type I diabetes, rheumatoid arthritis)type I diabetes, rheumatoid arthritis)

AIDSAIDS

AIDS is a disease in which the immune AIDS is a disease in which the immune system loses its ability to fight off system loses its ability to fight off pathogens and cancers.pathogens and cancers.

Caused by the HIV virusCaused by the HIV virus

Transmitted by the transfer of body fluids & Transmitted by the transfer of body fluids & needles. needles.