Chapter 40
The Immune System
*The ____________________ is the body’s main defense against _________________.- Pathogens = __________________________.______________ = To fight _____________ through the production of _______ that inactivate foreign substances or other cells.*** There are _________ types of defense mechanisms that fight infection: ________________ _______________ and _____________________.
immune system
Function
pathogens
A disease causing agent
cellsinfection
two
defensesnonspecific
specific defenses
I. Nonspecific Defenses (includes both _______________ and __________________ barriers)A. First Defenses
1. Keeping pathogens _________.a. includes
___________________ _____________________ _____.
b. The __________ is the most important and it keeps
_____ pathogens out!c. ________________ can kill
many different types of ______________.
physical chemical
skin
outskin, mucus
sweat and tears
most
secretions
bacteria
SKIN
1) _____________________ contain __________ which can kill the ____________.
2) ________ and ___________ make an _____________ environment that kills bacteria.
3) Openings like the mouth and nose are protected by _________ and _____________________.
Mucus, saliva, and tears
lysozymescell walls
sweat glandsOil
acidic
mucusciliated cells
B. Second Line of Defense
1. What happens when the pathogens enter your body and multiply?
a. The _________________________ is activated = a_________________________
reaction to ___________________ caused by injury or ________________.
1) When a ___________ is detected, the immune system makes millions of __________________________ (they fight infection!).
inflammatory response
nonspecific defensetissue damage
infectionpathogen
white blood cells
Red blood cells
Platelets
White blood cell (T-Cell)
2) The blood vessels near the wound _________ and to move the cellinto the infected area.
3) Many of the white blood cells are _____________ that __________
the pathogens.
4) This response causes ___________________________.painswelling, redness, and
engulfphagocytes
expand
b. The immune system can also ________ the ________________________ of the body when it is necessary.
1) __________ = A raise in the body’s core temperature in response to
__________.
2) The temperature increase can kill many sensitive pathogens that can only ________________ at ___________________________.
3) An increase in temperature also ____________________________ which moves the white blood cells through the body ___________.
core temperature
Fever
infection
survivespecific temperatures
speeds up the heart rate
faster
raise
C. Interferon
1. Some cells that are infected with a virus makes a group of
________________called___________.
a. Interferon __________
the virus’s ability to make proteins and reproduce.
proteinsinterferon
slows
II. Specific Defenses
A. If a pathogen can get past the_____________________________ the immune system will attack a _____________ type of pathogen through an __________________.
B. The _____________ that triggers the immune response is called an
______________. (ex. Viruses, bacteria, etc.)
nonspecific defense
specificimmune response
substance
antigen
1.Antigens are recognized by ________ types of _______________________.
a) _________________ (B cells)
- Provide immunity against antigens and pathogens in the ____________.
- This is called ___________________.
twolymphocytes
B- lymphocytes
body fluids
humoral immunity
b) ______________ (T cells)
- Defend against ________________ and pathogens inside living cells.
- This is ______________ __________.
T Lymphocytes
immunitycell-mediated
abnormal cells
C. Humoral Immunity
1. B cells recognize a pathogen and then __________ rapidly, making
___________________and
__________________.
a) Plasma cells release ___________ = proteins that
recognize and
bind to antigens.
multiply
plasma cells
memory B cells
antibodies
2.The _______________ travel in the ___________________ to get to the foreign pathogens where they overwhelm them.
3.The plasma cells die out and ________ producing the antibodies as the infection is overcome.
a) Millions of ______________________ cells are left over and are able to produce the __________________.
b) If the __________ antigen enters the body again, a _________________ is triggered and the memory B cells ____________ to make new _______________________ with same antibodies.
stop
memory B cells
same antibodies
samesecondary response
dividenew plasma cells
bloodstreamantibodies
Figure 24.9
PRIMARY RESPONSE(initial encounterwith antigen)
Antigen
Antigen receptoron a B cell
Antigen bindingto a B cell
Memory B cell
Antibodymolecules
Plasma cell
Cell growth,division, anddifferentiation
SECONDARY RESPONSE(can be years later)
Cell growth,division, and furtherdifferentiation
Larger cloneof cells
Plasma cell
Antibodymolecules
Later exposure to same antigen
Memory B cell
Clone ofcells
Primary and Secondary Response Curves
D. Antibody Structure
1. Antibodies are shaped like a _____.
2. ____ identical binding sites for antigens.
3. Like an _____________, the _____________ of the binding site determines which antigens it can bind with.
Antigen-bindingsites
“Y”
shapeenzyme
2
Figure 24.7
Antigen molecules
Variety ofB cells in a lymph node
Cell growthdivision, anddifferentiation
Clone of manyeffector cellssecretingantibodies
Antibodymolecules
Antigen receptor(antibody oncell surface)
Endoplasmicreticulum
a) Because there are so many different _______ of antigens, our bodies must
make ________________ of different types of ____________________.
E. Cell-Mediated Immunity
1. Cell Mediated Immunity = The body’s defense against it’s ________________
when they turn ___________ the body (i.e. cancerous cells, virus-infected cells, fungi, protists).
2. Antibodies __________________ destroy them.
types
cannot alone
againstown cells
antibodiesmillions
3. T-cells divide and _________________ (become specialized in structure and function)
a) ____________________
- Locate and ___________________ bacteria, fungi, or foreign tissue that has the
____________.
b) _____________________- Activate _______ T cells to divide and
also stimulate B cells to ______________.
- They make ___________________.
antigen
Killer T Cells
destroy
memory T Cells
Helper T Cells
differentiate
differentiateKiller
Figure 24.13A
Microbe
Macrophage
Antigen from microbe(nonself molecule)
Self protein
Self proteindisplayingantigen
T cell receptor
Bindingsite for self protein
HelperT cell
Binding sitefor antigen
Helper T Cells
c) __________________________
- Releases a substance that ___________________________ or shuts
down the _______________ when the __________ is under control.
d) _________________________
- Will cause a _________________________ if the same antigen appears again.
INFECTED CELL
CytotoxicT cell
Foreignantigen
Holeforming
Suppressor T Cells
slows the developmentkiller T Cells
infection
Memory T Cellssecondary response
F. Transplants
1. Killer T cells can make _____________________ difficult.
2. Body cells have _____________________ on their surface that the recipient’s ____________ do not recognize.
organ acceptance
marker proteinsT cells
a) The immune system begins to ________________ the transplanted organ
in a process called ___________________.
b) This is why it is important for __________ to have many of the same cell markers as
the __________________.
c) Recipients must take drugs that _____________ cell-mediated immunity.
attack
suppress
recipient
donors
rejection
III. Acquired Immunity
A. Active Immunity
1. _________________________ = Immunity produced from a vaccine.
2. Vaccination = The injection of a ___________________________ in
order to produce ____________________.
Active Immunity
weakend pathogenimmunity
a) More than _____ different human diseases can be _________________ by vaccination.
b) Modern vaccines ____________ the immune system to create millions of different _______________________.
3. Active immunity can result from _________________ or from _____________.
20
stimulate
prevented
plasma cells
natural exposurevaccines
B. Passive Immunity1. ___________________ = Antibodies from
____________________ are injected into the bloodstream.
2. Passive immunity is __________________ because the body’s immune system will ______________ the foreign antibodies.
3. Passive immunity can also occur __________________ or ________________.
Ex.- Antibodies produced by a pregnant mother can be passed through the placenta (or through breast milk) to the fetus. This protects an infant inthe first few month’s of it’s life.
naturally
another animalPassive immunity
temporary
intentionally
attack
AIDS (Acquired Immune Deficiency Syndrome)
I. AIDS is a ___________ infection.
- AIDS destroys_______
__________.
- The cause of AIDS is
_______ (Human Immunodeficiency Virus)
HIV
T cells
Helper
viral
How HIV worksA. HIV targets ______________
1. HIV is a _______________ = a virus that carries it’s information in the form
of _____.2. When a HIV virus attaches to a helper T Cell, it injects it’s RNA which uses a
process called ______________________.a. The ____________ forces the cell’s DNA to make copies of itself. Some become part of the original cell’s ______ while others
stay in the cytoplasm.
reverse transcriptase
retrovirus
RNA
Viral RNA
DNA
Helper T Cells
3. When the ______________ is activated, the host cell begins to make the parts of the
________.
a. These parts are assembled and then
__________ the cell to infect other cells.
Virus emerging from a T cell.
Viral DNA
virus
leave
B. They grow ________ T-cells therefore they are not affected by ____________.
1. Over time _________ are destroyed which
lowers ____________ and _____________
immunity.
a. The fewer number of __________
means that the body is more susceptible to other
__________.
2. A person is diagnosed with AIDS when their
T cell count goes below ________.200/mm3
diseases
T cells
humoralcell-mediated
T cells
antibodiesinside