Transcript The Immune System - James B. Conant High School

The Immune System
Sneeze
History of Identifying Pathogens
Robert Koch (1843-1910): “father of disease”
-research focused on anthrax (bacteria).
Koch’s Postulates:
-rules for determining the cause of a disease
or illness.
Infectious Diseases
Pathogens: anything foreign that enters your
body and can make you sick.
Examples- bacteria, viruses, protists, fungi &
non-harmful substances.
Modes of Transmission:
Air
Food
Water
Person-to-person contact
Animal bites (vector)
Human Diseases & Conditions
Disease/Condition
Pathogen
Mode of Transmission
AIDS
Virus (HIV)
bodily fluids
Common Cold
Coronavirus
air, physical contact
Malaria
Plasmodium falciparum
mosquitoes
Measles
Paramyxovirus
air, physical contact
Botulism
Clostridium botulinum
contaminated food
Tetanus
Clostridium tetani
physical contact
Athlete’s Foot
Trichophyton rubrum
physical contact
First Line of Defense: Barriers
Structures:
Skin
Oil (sebum)
Mucous Membranes
Tears
Saliva
Ear wax
Hair/Cilia
Second line of Defense:
NonSpecific Immunity
NonSpecific Immunity includes:
1. Inflammatory Response
2. Temperature Response
3. Proteins
1. Inflammatory Response: series of reactions that
suppress infection and speed recovery.
a. Histamine released (Increases blood flow to site of
injury/infection; can cause redness, swelling, warmth,
and pain)
b. Phagocytes- white blood cell that ingest and destroy
pathogens.
Examples: Neutrophils, Macrophages &
Natural Killer Cells – attack pathogen infected cells.
2. Temperature Response-Fever: sign body
is responding to infection; suppresses
growth and reproduction; promotes action
of white blood cells.
3. Complement System- Proteins:
20 different proteins used to fight off
pathogens,
Exp.: Interferon- protein that
inhibits reproduction of viruses.
Third Line of Defense:
The Immune System & Response
Immune System Structures
1. Bone Marrow
-Produces white blood cells lymphocytes
-Two types: B cells & T cells
2. Thymus – gland in the chest
-Place of maturation of T-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:
Let the Battle Begin!
1. Macrophage engulfs a pathogen.
2. Helper T-cells (lymphocyte) bind with macrophages
to fight the pathogen and release specialized proteins
(Interleukin).
3. Specialized proteins stimulate additional protein
release that stimulate additional Helper T-cells and
Cytotoxic T-cells.
A. Cell-Mediated Immune Response
-Cytotoxic T-cells & Suppressor T-cells
-destroy infected cells
-shut down response after pathogens are cleared
B. 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
-Antibodies are stored for future use
-Memory Cells (lymphocytes) are produced and remain in
the body long term for future pathogen attacks.
Immunity & Vaccination
1. Immunity-the ability to resist an infectious
disease.
-Memory cells
-Vaccinations
2. Vaccine-solution that contains a dead or
weakened pathogen.
-Body initiates a primary immune response.
Memory cells remain for future possible infections.
-Booster shots
Problems of the Immune System:
Allergies
Asthma
Autoimmune Diseases- immune system attacks
your own body cells. (lupus, MS,
type I diabetes, rheumatoid arthritis)
HIV and AIDS
• AIDS- Acquired Immunodeficiency Syndrome
– The immune system loses its ability to fight off pathogens and cancers
• AIDS results from infection by HIV
– HIV-Human Immunodeficiency Virus
Destroys Helper T cells cripples the immune system leads to AIDS
• Opportunistic Infections-illnesses caused by pathogens that produce
disease in people with weakened immune systems
– Usually these pathogens don’t create problems in healthy people
• HIV does NOT cause death, but AIDS is fatal
– Death caused by weakened immune system’s inability to fight
opportunistic infections and cancers
• HIV is transmitted by body fluids and contaminated needles
*PLAY DISCOVERYEDUCATION VIDEO*
Type of Cell
Function
Phagocyte
Ingest and destroy pathogens.
Neutrophil
Type of phagocyte, most abundant, attacks and destroys
pathogens.
Macrophage
Type of phagocyte, attacks and destroys pathogens.
Natural Killer Cells
Attack pathogen infected cells, cancerous cells, and virus
infected cells.
B Cells
Lymphocyte, made in bone marrow, changes in to Plasma
cells.
T cells
Lymphocyte, made in bone marrow, sent to thymus for
maturation.
Helper T cells
Lymphocyte, helps with the initial steps of the immune
response by binding with a macrophage.
Cytotoxic T cells
Lymphocyte, destroys infected cells, cancer cells, and
parasites.
Suppressor T cells
Lymphocyte, shuts down the immune response when all
pathogens are gone.
Plasma cells
Lymphocyte, type of B cell that makes antibodies.
Memory cells
Lymphocyte, attacks pathogens later, not the first time.