Download Immunity

Lesson 5.1
Immunity
By Carone
Fitness
Immunity
Immunity
To protect you from being
sick all the time, your body is
constantly defending itself
against infectious agents.
Immunity is the body’s
natural defenses against
infection.
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Immunity
Immunity
There are two types of
immunity:
 Non-specific immunity
 Specific immunity
Immunity
Non-specific Immunity
Non-specific immunity is the body’s
natural defense that protects against
infectious agents in a universal way.
Non-specific immunity has four forms:
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Physical barriers
Chemical barriers
Body cells
Inflammatory response
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Immunity
Physical Barriers
The first line of defense against
infection is provided by physical
barriers. The main barrier is
your skin. Unbroken skin keeps
pathogens from entering your
body’s tissues.
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Physical Barriers
Mucus membranes are the
soft, skin-like linings of your
nose, mouth, and lungs that
produce mucus. This mucus
traps pathogens and keeps
them from entering your body.
Some mucus membranes are
lined with cilia.
Cilia are tiny hairs that catch
pathogens before they enter
the body. The pathogens are
then expelled when you sneeze
or cough.
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Immunity
Chemical Barriers
The enzymes in tears and
saliva are chemical barriers
that help destroy bacteria.
Pathogens in food can be
eliminated by the gastric juices
in your stomach, which are
very acidic. These gastric
juices also serve as a
chemical barrier.
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Body Cells
Once pathogens reach your
bloodstream, your body alerts certain
cells of the invasion. These cells are
known as phagocytes.
Phagocytes are white blood cells that
group together to destroy foreign
organisms.
The process of phagocytes engulfing
and terminating pathogens is known as
phagocytosis.
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Immunity
Inflammatory Response
When your body is invaded by
pathogens, it triggers the inflammatory
response. The inflammatory
response is the body’s response to
foreign pathogens characterized by an
increased blood flow to facilitate the
movement of phagocytes into body
tissues.
Symptoms of inflammation include:
 Heat
 Redness
 Swelling
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Specific Immunity
Specific immunity is the body’s way
of fighting off pathogens that have
evaded its non-specific immunity.
During specific immunity lymphocytes
fight against the pathogens.
Lymphocytes are a kind of white
blood cell that can be found in blood
vessels and lymph vessels. There are
two main types of lymphocytes:
B
Cells and T Cells.
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Immunity
Specific Immunity
When B cells encounter a pathogen,
they begin to grow and multiple. The B
cells then develop into plasma cells.
The plasma cells release antibodies to
destroy the pathogen.
Antibodies are proteins that destroy or
neutralize pathogens. The antibodies
then remain in the blood to become
active if that same pathogen enters the
body again.
Immunity
Specific Immunity
There are two categories of T cells:
killer and helper cells.
Killer T cells are triggered to multiply by
the presence of abnormal body cells.
They attach themselves to the foreign
cells and release toxins to destroy
them.
Helper T cells aid B cells and control
other aspects of the immune system.
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Immunity
Prevention
In order to provide protection from
pathogens, your body develops a
natural resistance to those pathogens.
This is known as immunity.
Research and modern technology have
led to the creation of vaccinations.
Vaccinations provide antibodies that
are needed to fight off a certain
pathogen, should you ever be exposed
to it.
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Prevention
Other guidelines you can follow
to help prevent infectious
diseases include the following:
 Make sure to get good
nutrition, regular exercise,
and adequate sleep.
 Shower frequently in order
to keep your hair, skin, and
nails clean.
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Immunity
Prevention
 Avoid sharing eating or
drinking utensils with other
people.
 Wash your hands
frequently.
 Store and prepare food
properly.
Presented
By Carone
Fitness
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