The Immune SystemThe Immune System

Disease TransmissionDisease Transmission

Robert Koch… “father of disease”Robert Koch… “father of disease”

-research focused on anthrax-research focused on anthrax

--Koch’s Postulates:Koch’s Postulates:

rules for determining the cause of a rules for determining the cause of a disease or illness.disease or illness.

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

Infectious DiseasesInfectious Diseases

--PathogensPathogens – foreign particles – foreign particles Ex. Viruses + bacteriaEx. Viruses + bacteria

-Multiply in the body to cause infection-Multiply 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 MembranesMucous Membranes – epithelial tissue that – epithelial tissue that

protect the interior surfaces of the body.protect the interior surfaces of the body. TearsTears SalivaSaliva Ear wax Ear wax Hair/Cilia Hair/Cilia

Second line of Defense:Second line of Defense:If a pathogen penetrates the first line of defense...If a pathogen penetrates the first line of defense...

1. 1. Inflammatory ResponseInflammatory Response: series of reactions that : series of reactions that suppress infection and speed recovery.suppress infection and speed recovery.

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

bb. . PhagocytesPhagocytes – type of white blood cell. – type of white blood cell.• NeutrophilNeutrophils & s & MacrophagesMacrophages – attack pathogens – attack pathogens• Natural Killer CellsNatural Killer Cells – attack pathogen infected cells.– attack pathogen infected cells.

2. Complement System 2. Complement System – using proteins to fight off – using proteins to fight off pathogenspathogens

3. Interferon3. Interferon - protein that inhibits reproduction of - protein that inhibits reproduction of virusesviruses

4. Fever4. Fever - sign body is responding to infection; - sign body is responding to infection; suppresses growth and reproduction; promotes action suppresses growth and reproduction; promotes action of white blood cells.of white blood cells.

The 3The 3rdrd Line of Defense: Specific Line of Defense: Specific Defenses against a specific pathogen.Defenses against a specific pathogen.

Immune SystemImmune System – cells and tissues of your body that – cells and tissues of your body that recognize and fight off pathogens.recognize and fight off pathogens.

1. Bone Marrow1. Bone Marrow-Produces white blood cells -Produces white blood cells lymphocyteslymphocytes

-Two types: -Two types: B cellsB cells & & T cellsT cells

2. 2. ThymusThymus – – gland in the chestgland in the chest

-Place of maturation of T-cells-Place of maturation of T-cells

3. Lymph & Lymph Nodes3. Lymph & Lymph Nodes-Filter pathogens, lymphocytes-Filter pathogens, lymphocytes

4. 4. SpleenSpleen-Filters pathogens from blood-Filters pathogens from blood

5. Tonsils & Adenoids5. Tonsils & Adenoids

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

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

The The Immune ResponseImmune Response begins with the begins with the recognition of an recognition of an AntigenAntigen (pathogen). (pathogen).

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

-Begin with -Begin with helper T-cellshelper T-cells (lymphocyte) (lymphocyte) binding with macrophages to fight pathogens.binding with macrophages to fight pathogens.

1. 1. Cell-Mediated Immune ResponseCell-Mediated Immune Response--Cytotoxic T-cellsCytotoxic T-cells & suppressor T-cells & suppressor T-cells-destroy infected cells-destroy infected cells-shut down response after pathogens are cleared-shut down response after pathogens are cleared

2. 2. Humoral Immune ResponseHumoral Immune Response--B cellsB cells change into change into plasma cells plasma cells and produce and produce antibodiesantibodies..

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

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

Primary & Secondary Immune ResponsesPrimary & Secondary Immune Responses

o Some B cells turn into Some B cells turn into memory cellsmemory cellso Lymphocytes that will not respond the 1Lymphocytes that will not respond the 1stst time they meet an time they meet an

antigen, but will recognize and attack with later infectionsantigen, but will recognize and attack with later infectionso Explains why you get most diseases only onceExplains why you get most diseases only once

o Primary Immune ResponsePrimary Immune Responseo First time the body encounters an antigenFirst time the body encounters an antigeno Memory cells produced for that specific antigenMemory cells produced for that specific antigen

o Secondary Immune ResponseSecondary Immune Responseo Later infection by the same pathogenLater infection by the same pathogeno Memory cells respond faster and strongerMemory cells respond faster and stronger

o Exception: Cold and Flu virusesException: Cold and Flu viruses

Immunity & VaccinationImmunity & Vaccination

1. Immunity-the ability to resist an infectious 1. Immunity-the ability to resist an infectious diseasedisease

Memory cells Memory cells VaccinationsVaccinations

2. Vaccine-solution that contains a dead or 2. Vaccine-solution that contains a dead or weakened pathogen weakened pathogen

Body produces primary immune responseBody produces primary immune response• Memory cellsMemory cells

Booster shotsBooster shots

Problems of the Immune System:Problems of the Immune System:

AllergiesAllergies

AsthmaAsthma

Autoimmune DiseasesAutoimmune Diseases- immune system - immune system attacks your own body cells. (lupus, MS,attacks your own body cells. (lupus, MS,

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

HIV and AIDSHIV and AIDS AIDS- Acquired Immunodeficiency SyndromeAIDS- Acquired Immunodeficiency Syndrome

The immune system loses its ability to fight off pathogens and cancersThe immune system loses its ability to fight off pathogens and cancers AIDS results from infection by HIVAIDS results from infection by HIV

HIV-Human Immunodeficiency VirusHIV-Human Immunodeficiency Virus• Destroys Helper T cellsDestroys Helper T cellscripples the immune systemcripples the immune systemleads to leads to

AIDSAIDS Opportunistic InfectionsOpportunistic Infections-illnesses caused by pathogens that produce -illnesses caused by pathogens that produce

disease in people with weakened immune systemsdisease in people with weakened immune systems Usually these pathogens don’t create problems in healthy peopleUsually these pathogens don’t create problems in healthy people

HIV does NOT cause death, but AIDS is fatalHIV does NOT cause death, but AIDS is fatal Death caused by weakened immune system’s inability to fight Death caused by weakened immune system’s inability to fight

opportunistic infections and cancersopportunistic infections and cancers HIV is transmitted by body fluids and contaminated needlesHIV is transmitted by body fluids and contaminated needles

*PLAY DISCOVERYEDUCATION VIDEO**PLAY DISCOVERYEDUCATION VIDEO*

Summary of Cell Types:Summary of Cell Types: