1. Chapter 40
The Immune System

2. A disease causing agent
*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
pathogens
A disease causing agent
Function
infection
cells
two
nonspecific
defenses
specific defenses

3. 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
out
skin, mucus
sweat and tears
skin
most
secretions
bacteria

4. SKIN

5. Mucus, saliva, and tears
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 _____________________.
lysozymes
cell walls
Oil
sweat glands
acidic
mucus
ciliated cells

6. inflammatory response
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 defense
tissue damage
infection
pathogen
white blood cells

7. Red blood cells
Platelets
White blood cell (T-Cell)

8. 2) The blood vessels near the wound _________ and to move the cell
2) The blood vessels near the wound _________ and to move the cell into the infected area.
3) Many of the white blood cells are _____________ that __________
the pathogens.
4) This response causes ___________________________.
expand
phagocytes
engulf
pain
swelling, redness, and

9. specific temperatures speeds up the heart rate
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 ___________.
raise
core temperature
Fever
infection
survive
specific temperatures
speeds up the heart rate
faster

10. 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.
proteins
interferon
slows

11. 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
specific
immune response
substance
antigen

12. 1. Antigens are recognized by ________ types of _______________________.
a) _________________ (B cells)
- Provide immunity against antigens and pathogens in the ____________.
- This is called ___________________.
two
lymphocytes
B- lymphocytes
body fluids
humoral immunity

13. b) ______________ (T cells)
- Defend against ________________ and pathogens inside living cells.
- This is ______________ __________.
T Lymphocytes
abnormal cells
cell-mediated
immunity

14. 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

15. 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.
antibodies
bloodstream
stop
memory B cells
same antibodies
same
secondary response
divide
new plasma cells

16. PRIMARY RESPONSE
(initial encounter
with antigen)
Antigen
Antigen receptor on a B cell
Antigen binding
to a B cell
Cell growth,
division, and
differentiation
Clone of cells
Memory B cell
Plasma cell
Antibody
molecules
Later
exposure
to same
antigen
SECONDARY RESPONSE
(can be years later)
Cell growth,
division, and further
differentiation
Larger clone
of cells
Plasma cell
Memory B cell
Antibody
molecules
Figure 24.9

17. Primary and Secondary Response Curves

18. 1. Antibodies are shaped like a _____.
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-binding
sites
“Y” 2
enzyme
shape

19. Antigen molecules
Variety of B cells in a lymph node
Antigen receptor (antibody on cell surface)
Cell growth
division, and
differentiation
Clone of many effector cells secreting antibodies
Endoplasmic reticulum
Antibody molecules
Figure 24.7

21. a) Because there are so many different
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
millions
antibodies
own cells
against
cannot alone

22. T-cells divide and _________________
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 ___________________.
differentiate
Killer T Cells
destroy
antigen
Helper T Cells
Killer
differentiate
memory T Cells

23. Helper T Cells Microbe Macrophage
Antigen from microbe (nonself molecule)
Self protein
displaying
antigen
T cell receptor
Binding site for self protein
Helper
T cell
Binding site
for antigen
Figure 24.13A

24. c) __________________________
- Releases a substance that ___________________________ or shuts
down the _______________ when the __________ is under control.
d) _________________________
- Will cause a _________________________ if the same antigen appears again.
Suppressor T Cells
slows the development
killer T Cells
infection
Memory T Cells
secondary response
INFECTED CELL
Cytotoxic T cell
Foreign antigen
Hole forming

27. 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 proteins
T cells

28. 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
rejection
donors
recipient
suppress

29. 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 pathogen
immunity

30. a). More than _____ different human. diseases can be _________________
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
prevented
stimulate
plasma cells
natural exposure
vaccines

31. B. Passive Immunity
___________________ = 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.
Passive immunity
another animal
temporary
attack
naturally
intentionally

33. AIDS (Acquired Immune Deficiency Syndrome)
AIDS is a ___________ infection.
- AIDS destroys_______
__________.
- The cause of AIDS is
_______ (Human Immunodeficiency Virus)
viral
Helper
T cells
HIV

34. reverse transcriptase
How HIV works
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.
Helper T Cells
retrovirus
RNA
reverse transcriptase
Viral RNA
DNA

36. a. These parts are assembled and then
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.
Viral DNA
virus
leave
Virus emerging from a T cell.

37. B. They grow ________ T-cells therefore they
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 ________.
inside
antibodies
T cells
humoral
cell-mediated
T cells
diseases
200/mm3