Transcript The Lymphatic System

The Lymphatic System
What Is the Lymphatic System?
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A system of thin tubes that
run through the body
called lymph vessels
The liquid that is inside
these vessels is called
lymph
It comes from plasma that
fills empty spaces between
blood vessels, which is
called interstitial fluid, and
is collected by the lymph
vessels to make lymph
Lymph Nodes (or Glands)
Small round
structures found
along the larger
lymph vessels
 Found in 4 areas:
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Groin
Neck
Abdomen
Armpits
They make white
blood cells
Organs That are Part of the
Lymphatic System:
Spleen (abdomen)
 Tonsils (throat)
 Thymus (chest)
 Adenoids (back of
nose)
All these organs are
filled with white
blood cells that
filter blood and
collect harmful
bacteria and
viruses
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What Does the Lymphatic System
Do?
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Drains fluid back to the
bloodstream from the tissues
Filters lymph
Filters the blood
Fights infections
Draining Fluid Back to the Blood
Plasma leaks out of
capillaries into the
tissues to give food to
the cells
 The leaked plasma is
called interstitial fluid
 This fluid gets into
the lymph vessels
where it is eventually
returned to the blood
 It carries with it
waste from the cells
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Filtering Lymph
 The
lymph is filtered by the lymph
nodes
 In the lymph nodes are filled with
white blood cells that attack bacteria
and viruses
 Cancer cells often end up here
Filtering Blood
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The spleen filters the blood
– It destroys old worn out red blood cells
– It has white blood cells that attack viruses and
bacteria
Non-specific immunity
This is the body’s ability to protect itself against
a wide range of antigens without using
antibodies:
 White blood cells are made in lymph nodes
 Your lymph nodes or glands become swollen
when you are sick because they are working
to make cells to fight infections
 White blood cells move out of capillaries by
diapedesis and enter the lymphatic system to
reach the site of infection
 Once they reach the pathogen they surround
and destroy it through phagocytosis
Diapedesis
Phagocytosis
When the Lymphatic System Goes
Wrong
Elephantiasis
-Happens when the
lymphatic vessels
are blocked due to
a parasite
When the Lymphatic System Goes
Wrong
Lymphedema
-Happens when the
lymphatic vessels
are blocked
-This may be caused
by an injury to the
lymph vessels or it
may be inherited
Specific immunity
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The body’s ability to protect itself against
a particular antigen using specific
antibodies
You can become specifically immune
naturally (by being exposed to an infection
like chicken pox or whooping cough) or
artificially, by being given a vaccine
**Vaccines do not cure you of diseases –
you need to be vaccinated BEFORE getting
sick!
Vaccines
 Were
investigated by Edward Jenner
in the 1700s.
 Later, Pasteur conducted a few
experiments on fowl cholera 0ver
100 years later
Vaccine Manufacturing
Attenuated vaccines are prepared from
living bacteria or viruses. Manufacturers
select strains that have lost their power to
cause disease to make these
 Inactivated vaccines are prepared from
bacteria or viruses that have been
inactivated or killed by chemicals, heat or
UV rays
 Vaccines can also be prepared through
genetic manipulation, where scientists
replace or remove genes in viruses and
bacteria that cause disease
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Different vaccines can sometimes have
different side effects
The Difference between
Antibiotics and Vaccines
• Antibiotics cure disease by killing or
injuring bacteria
•Antibiotics only treat bacterial
infections. Antibiotics are useless against
viral infections (for example, the common
cold) and fungal infections (such as
ringworm)
•There are broad-spectrum and narrow
spectrum antibiotics
Class Assignment – Answer the
following questions on loose leaf
(due at the end of the class)
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Describe the lymphatic system in a
paragraph.
What are lymph nodes?
What organs are part of the lymph
system?
Why do your glands get swollen when
you are sick?
What are the functions of the lymphatic
system. Describe fully in paragraph
form.