Immunity
Name of the system: Immune System
What is Immunity?
• Immunity: ability to resist
certain pathogens
• Pathogen- an “agent of
disease.” It is the disease
causer
• EX of pathogen: HIV, Flu, or
common cold
How do we get Pathogens?
• Pathogens are transmitted
by:
• Airborne (i.e. Influenza)
• Contaminated drinking water
• Vector- an organism that
carries a disease (i.e. tick)
• Fluids (ex: HIV)
Does anyone know what
cells fight infections?
•White blood cells fight
infections
•They are also called
lymphoctyes
Kinds of Lymphocytes
B-Cells
1. Antibodies
2. Memory B
T- Cells
1. Helper T
2. Cytotoxic T
3. Memory T
T- Cells
Helper T
Assist Antibodies
Cytotoxic T
Killer T’s
“Cell Police”
Remember previous
pathogens
Memory T
help produce
specific antibodies
Specific Defense
• Pathogen have antigens on
them
• Antigens- trigger the immune
response
• Antigens have a protein,
carbohydrate, or lipid on their
surface
An Antigen
These are
proteins,
carbs, or
lipids
on the
surface
They are often
called
surface
“proteins”
ANTIBODIES
• Shaped like a Y
• Shape is Y so the antigen
has 2 places to bind
• EX: Virus attaches to
antigens, clumps them, &
attracts WBC’s
Antibody Shape
ANTIGEN BINDED
Steps to an Infection
• 1) Pathogen Invades
• 2) Antigens are recognized by
a body’s B’cells
• 3) B cell’s produce specific
antibodies and are released
into the blood
• 4) Memory B & T cells are
made to remember
Vocabulary
• Immunity
• Memory T Cell
• Pathogen
• Cytotoxic T cell
• Vector
• Lymphocyte
• Antibody
• Antigen
• Helper T cell
STOP
Homeostasis Disrupted
• Homeostasis is disrupted in 4
MAJOR ways:
• 1)HIV/AIDS
• 2) Organ Transplant
• 3) Cancer
• 4) Allergies
HIV/AIDS
• HIV= Human Immunodeficiency
Virus
• AIDS = Auto Immune
Deficiency Syndrome
• HIV is the virus you are
infected with.
• HIV attaches to T-Helper cells,
and decreases immunity
• This is why people with
HIV/AIDS are susceptible to
many different kinds of
infections
Cancer
• Not always recognized as
foreign, because cancer is
made by your own cells
• Cytotoxic T-cells are
constantly surveilling for
cancer
• Causes of cancer: viral,
genetic, or chemical (radiation)
Allergies
• Antigens from allergens (i.e. pet
dander) bind to Mast cells
• Mast cells release Histamine
• Mast cells are another type of
immune cells, common in nasal
passages
• Histamine is what causes the actual
reaction
• *ADD allergens are harmless is
general, but their antigen is
recognized as foreign
Organ Transplant
• Cytotoxic T-cells ATTACK the
new organ
• The new organ is seen as
foreign
• Patients are put on
immunosuppresants for life
STOP
2 kinds of
Immunity
Active
Immunity
Natural
Passive
Immunity
Natural
Acquired(Maternal)
Acquired
Active Immunity: the body
makes its OWN antibodies in
response to an antigen
• Active Natural: • Active
Acquired:
• an antigen
enters your
body and YOU
make
antibodies to
fight it
• A Vaccine
• EX: Chicken
Pox
Vaccine
• A vaccine is weakened or
mild form of a pathogen
• This weakened form
stimulates an immune
response to produce specific
antibodies to this particular
pathogen
Passive Immunity: lasts a
LIMITED amount of time
• Acquired
Passive:
• Natural
Passive:
•
When
a
• You are
mother
INJECTED with
breastfeeds
antibodies
her child she
• EX: Rabies
gives the child
Shots/anti-venom
antibodies
STOP
• HIV Immune Video