Transcript Protecting Yourself from Infectious Disease

October 13, 2009
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Your body has many ways of fighting diseasecausing bacteria, viruses, and other pathogens.
Skin
Mucous Membranes
Chemicals
Your body also has separate defense systems
like the inflammatory response and the
immune system.
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Your bodies first line of defense helps keep
many pathogens out of the body.
Your skin is part of the physical barriers that
block out pathogens.
Your skin uses chemicals, such as sweat and
oil, to kill pathogens that settle on your body.
Your skin is always nonstop repairing itself so
pathogens cannot get through (cuts).
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Soft tissues that line the nose, mouth, throat,
digestive tract, etc.
Make slimy material known as mucus
Pathogens get caught in the mucus lining while air
is carried to lungs.
-Trap pathogens
Cilia- tiny, hair-like structures that line tubes in
body.
Move mucus to back of throat, then by
swallowing, pathogens are sent to the stomach
where they are destroyed.
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Many chemicals in your body destroy
pathogens.
Sweat is acidic, and it inhibits the growth of
bacteria.
Your stomach secretes acids that not only help
digest food but they also help kill bacteria.
Tears contain protein that kill bacteria.
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Sometimes pathogens cross protective barriers
(skin and mucous membranes).
Inflammation is the second way your body
protects itself.
Inflammation- a reaction to injury or infection
that is characterized by pain, redness, and
swelling.
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When protective barriers are broken and part
of your body becomes infected, the area
becomes inflamed (gets hot).
Blood vessels expand; more blood to the
injured area.
Pus- yellowish substance that build up around
injury.
-Dead or injured body cells that were
fighting bacteria and dead and injured
bacteria.
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Made up of certain types of blood cells and
proteins called antibodies.
Lymphatic system- a network of vessels that
carry lymph throughout the body.
Picks up fluid from all over the body and
sweeps up bacteria and viruses and carries
them to the lymph nodes.
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Lymph nodes are filled with white blood cells.
White blood cells- cells in the blood whose
primary job is to defend the body against
disease.
Some WBCs produce antibodies that bind to
pathogens and warn other WBCs to destroy the
pathogen.
Swelling lymph nodes= increase in WBCs to
fight off infection.
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System’s defense takes time to defeat
pathogens and disease.
Cells of your immune system work to fight a
specific pathogen, as opposed to your bodies
other defense (skin, mucous membranes, etc.)