the lymphatic system€¦ · the immune system includes vessels and organs of the lymphatic system...
TRANSCRIPT
The Lymphatic System
The Lymphatic System
The Lymphatic System
Carries essential nutrients to the cells
Collects cellular waste
Plays an important role in the immune system of the
body
Lymph
A fluid that fills the spaces
between the blood vessels and the
body cells (interstitial fluid)
Derived from blood, mainly plasma
Made up mostly of water and
circulates in the lymphatic
vessels
Functions of the System
To collect excess lymph and
return it to the blood
circulation, along with any
waste that may be collected
To carry elements of the
immune system such as
antibodies and WBC that will
neutralize antigens (viruses
& bacteria)
To transport molecules such as
fats
Lymphatic Vessels
Similar to blood vessels, they are located near them
They carry lymph and return it to the blood by emptying it into two subclavian veins near the heart (right vein for upper body, left vein for lower body)
Lymph circulates as a result of the contracting of the muscles on the lymphatic vessels (like blood in veins).
Lymph Nodes AKA Ganglions
Small round structures found along lymph vessels
Found in 4 areas:
Groin, neck, armpits, abdomen
During an infection such as tonsillitis or the flu, lymph nodes swell and harden
Lymph is filtered by lymph nodes, which are filled with white blood cells that attack bacteria and viruses
They make WBC
Organs of Lymphatic System
Spleen: in abdomen
Tonsils: in mouth
Thymus: underneath heart
Bone marrow: in long
bones
These organs are filled with
WBC that filter blood and
collect harmful bacteria and
viruses
Spleen
The spleen filters blood. It destroys old worn red
blood cells. It has WBC that attack viruses and
bacteria
The Immune System
Includes vessels and organs of the lymphatic system as
well as other structures or cells, such as white blood
cells, which help to protect the body
Immunity: ability of the human body to protect
itself against foreign antigens
Antigens are viruses, bacteria, abnormal cells or any
other substances that can trigger a reaction of the
immune system
Antibody: substance produced by certain white blood
cells and that is able to neutralize a specific antigen
Non-Specific Immunity
Human body’s ability to protect itself against a wide range
of antigens (white blood cells)
Skin acts as a barrier and is one of the mechanisms of
non-specific immunity
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 outside of capillaries through a
process called diapedesis and enter the lymphatic system
to reach the site of infection, the white blood cells will
circle the antigens and form pseudopods
Once they reach the pathogen they surround and destroy it
through phagocytosis
Diapedesis
Phagocytosis
Specific Immunity
Human body’s ability to protect itself against a
particular antigen using specific antibodies
Immunity can be acquired in two ways:
Natural acquisition: being exposed to an infection
like chicken pox.
Cells of immune system have a memory of the antibodies
produced by white blood cells to fight against the antigen
causing the infection. If the antigen enters the body again,
body can produce the specific antibodies quicker, and the
person will not develop the illness again
Specific Immunity
Immunity can be acquired in two ways:
Artificial acquisition: being given a vaccine. Vaccines contain
dead/weakened antigens which trigger the production and
memory of antibodies without causing the illness. Vaccinated
person has immunity to that illness if they would encounter it.
**Vaccines do not cure you of diseases – you need to be
vaccinated BEFORE getting sick!
Basically…
General immunity is like an on-going security system
Specific immunity is like someone’s picture being posted
and being banned from entering a building
Vaccines
Substance that, when introduced into an organism, stimulates the immune system; which then manufactures specific antibodies and immunizes the individual against a given disease.
What are they used for?
To protect the health of the people that receive them which will prevent them from developing diseases with dangerous consequences
How does it work?
They contain antigens (bacteria, viruses, virus fragments, etc.) that are weakened and cannot transmit disease. The body still produces antibodies to eliminate these antigens that will be effective against the real disease.
Vaccines
Cowpox and Smallpox – The First Vaccine
Herd Immunity
Vaccines before travelling to certain countries
Refreshing vaccines
The Difference between Antibiotics and
Vaccines
Antibiotics cure disease by killing or injuring bacteria
Although antibiotics are useful in a wide variety of
infections, it is important to realize that antibiotics only
treat bacterial infections.
Antibiotics are useless against viral infections (for
example, the common cold) and fungal infections (such as
ringworm).