Name__________________________Date_________________Hour___________1
35.1
Summarize Koch’s Postulate
What are symbionts and pathogens?
35.2 Defenses
Against Infection
Nonspecific Defenses
The body’s first defense against pathogens is a combination of
____________________________and chemical __________________
1.)
2.)
3.)
4.)
5.)
6.)
These barriers are called _____________________________because they act
against a wide range of pathogens.
First Line of Defense
The most widespread nonspecific defense is the_________________________.
Very few pathogens can penetrate the layers of dead cells that form the skin’s
surface.
Other defenses protect parts of the body not covered by skin
1.) _________________2.) _______________3.) ___________
___________________, ____________________, &_______________________contain
lysozymes that breaks down bacterial cell walls.
Mucus in your nose and throat traps_____________________.
cilia push the mucous-trapped pathogens away from your lungs.
Stomach secretions destroy many pathogens that are swallowed.
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Second Line of Defense
If pathogens make it into the body, through a cut in the skin, the body’s second
line of defense swings into action.
These mechanisms include
– ____________________________________
– ____________________________________
-____________________________________
Inflammatory Response
The ___________________________________causes infected areas to become
red, painful, and inflamed.
Pathogens stimulate cells called mast cells to release chemicals ___________________.
Histamines increase the flow of________________ and
___________________to the affected area.
Fluid leaking from expanded blood vessels causes the area to swell.
White blood cells move from blood vessels into infected tissues.
Many of the white blood cells (__________________) engulf & destroy bacteria.
All this activity may cause a local rise in____________________________.
That’s why a wounded area sometimes feels warm.
Interferons
Viruses infect body cells, host cells produce proteins.
These proteins help block__________________________.
Interferons are ________________ that “interfere” with viral growth.
Interferons slow down the progress of infection & “buy time” for immune
defenses to respond.
Fever
The immune system also releases chemicals that increase body temperature,
producing a______________________________.
The increased body temperature may stop the growth of some pathogens.
Higher body temperature also speeds up parts of the immune response.
Nonspecific Defenses
What are the body’s nonspecific defenses against pathogens?
Answer below
________________________________________________________________________
_______________________________________________________________________
Recognizing “Self”
A healthy immune system recognizes all cells & proteins that
_____________________the body as “_______________________.”
Recognizing “self” is essential.
Name__________________________Date_________________Hour___________3
The immune system controls powerful cellular and chemical weapons that could cause
problems if turned against the body’s own cells.
Recognizing “Nonself”
–The immune system recognizes ____________________organisms as
“__________________.”
–Once the immune system recognizes “_________________,” it ________________
–After encountering a specific invader, the immune system “remembers” the invader
–This_______________________, _________________, and ___________________-the
immune response.
Antigens
–Antigen (__________________) -a _______________________that can stimulate an
immune response.
–Antigens are located on surfaces of_______________, ________________,
or__________________________.
–Immune system responds by _______________________that ________________the
invaders or produce proteins
–antibodies (________________________)
1.______________________(good guy) _________antigens (bad guy) for destruction
2.The body makes up to 10 billion different antibodies.
3.The shape of each type of antibody allows it to attach to one specific antigen.
Lymphocytes
The main working cells of the immune response are
–B lymphocytes (____________________)
–T lymphocytes (____________________).
B cells are produced, & mature in, in___________________________.
B cells have embedded _____________________and discover
_______________________in body fluids.
Lymphocytes
T cells are produced in bone marrow
mature in the ___________________________(endocrine gland.)
T cells must be presented with an antigen by infected body cells or immune cells
that have encountered antigens.
Lymphocytes
–Each ________cell and ____________ cell recognizes one specific antigen.
–A person’s ______________________determine the particular B and T cells that are
produced.
–Both types of cells travel to ___________________and the ___________________,
where they will encounter antigens.
Specific Defenses: The Immune System
What is the function of the immune system’s specific defenses?
Answer Below
________________________________________________________________________
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Humoral Immunity
Humoral immunity-The immune response that defends against antigens in body fluids
1.) _____________________2.) _____________________
–B cells play the ___________________________________
–When pathogens invades the body, its ____________________are recognized by
____________________________on the surfaces of the B cells.
–Antibodies are the _______________________________
Humoral Immunity
Antibody
~shaped like the letter _____
~two _______________antigen-binding sites.
The shapes of the binding sites lets an antibody recognize a specific antigen with
a_______________________________________________.
Humoral Immunity
When an antigen binds to an antibody,
__________cells stimulate the ____________cell to grow and divide rapidly.
That growth and division produces many B cells of two types:
1.) ______________________________________
2.) ______________________________________
Plasma Cells
*Plasma cells produced
*Plasma cells release _____________________________
*Antibodies are carried through the________________________.
*Antibodies recognize & bind to ___________________________
*When antigens are bound, they __________________________the immune system to
________________________& ____________________________the invaders.
*Some types of antibodies can disable invaders until they are destroyed.
Memory B Cells
Plasma cells _____________________after an infection is gone
some B cells that recognize a particular antigen remain alive.
These cells, called________________________________, react quickly if the
same pathogen enters the body again.
Memory B Cells
Memory B cells rapidly produce ______________________________to battle a
returning pathogen.
This secondary response occurs much ___________________________than the first
response to a pathogen.
Immune memory helps provide long-term immunity to certain diseases and is the
reason that vaccinations work.
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Cell-Mediated Immunity
Another part of the immune response is
called_____________________________.
This immune system defends the body against _______________,
______________, and single-celled__________________________________.
T cells also protect the body from its own cells when they
become________________________________________.
When a cell is infected by a pathogen or when a phagocyte consumes a pathogen,
the cell ______________________________a portion of the
______________________on the outer surface of its membrane.
This membrane attachment is a signal to circulating
_____________________called helper T cells.
Activated helper T cells divide into more ________________________
They go on to activate
________________________
which activate _____________________________________
& produce _______________________________________
Cytotoxic T (killer T cells) cells ________________________body cells infected
with a particular antigen and kill the cells.
They kill infected cells by puncturing their membranes or initiating apoptosis
(_______________________________________).
Memory helper T cells enable the immune system
___________________________if the same pathogen enters the body again.
Another type of T cell, called suppressor T cells, inhibits the immune response
once an infection is under control.
They may also be involved in preventing autoimmune diseases.
Although cytotoxic T cells are ___________________in the immune system, they
make the acceptance of ___________________________________________________
When an organ is transplanted from one person to another, the normal response of
the recipient’s immune system would be to recognize it as___________________. T cells
and proteins would damage and destroy the transplanted organ in a process known as
rejection.
To prevent organ rejection, doctors search for a donor whose cell markers are
nearly identical to the cell markers of the recipient.
Organ recipients must take_______________________—usually for the rest of
their lives—to suppress the_____________________________________________.
The Immune System in Action
What are the body’s specific defenses against pathogens?
Answer__________________________________&_____________________________
Name__________________________Date_________________Hour___________6