Download The Immune and Nervous System

The Immune System
What is the Immune System?
• A group of defenses that
protects the body against
disease-causing organisms.
• Pathogen- Any disease
causing organism.
First Line of Defense
• Skin- The skin keeps most pathogens from
entering into the body.
• If the skin is cut or torn, pathogens can get in.
• Respiratory System- Mucous and cilia in your
windpipe trap pathogens.
• Sneezing and coughing gets rid of these trapped
pathogens.
First Line of Defense
• Digestive System- Saliva and acids
work to kill pathogens.
• HydroChloric Acid- Digests your food
and many pathogens you eat.
• Circulatory System- White blood
cells attack and kill pathogens.
• Increasing your body temperature
(fever) kills pathogens too.
Inflammation
• When an area is infected with pathogens, it
becomes inflamed.
• Inflamed areas become red, swollen and painful.
• White Blood Cells go to inflamed areas to fight
off the pathogen.
• Puss- Dead white blood cells that have died fighting
off the infection.
Active Immunity
• 1. A pathogen (bacteria, virus) enters your
body, and you get sick.
• 2. White Blood Cells produce AntibodiesSpecific proteins that attack the pathogen.
• 3. The pathogen dies, and you get better.
• 4. That Antibody stays in your blood incase the
pathogen comes back later.
• 5. If the pathogen comes back, white blood
cells make more Antibodies to fight off the
attack, keeping you from getting sick.
Pathogen
enters your
body.
Antibodies are
made.
Pathogen
dies.
Active
Immunity
If pathogen
returns,
antibodies
build up again
Antibodies
stays in
your blood.
Vaccination
• Process of giving a vaccine to
help give active immunity.
• Vaccine- Preparation of dead
or damaged pathogens.
-After you get the vaccine, your body will begin
making antibodies to fight off the pathogen.
-If you ever get the real pathogen, your body will
know how to kill it quickly with antibodies.
-Your body REMEMBERS which antibodies
attack which pathogens!
Passive Immunity
• When antibodies are made in another
person or animal, and then given to
you.
• Newborn babies have Passive
Immunity from antibodies in their
mother’s blood.
• This Passive Immunity only last for a
few months, so the baby will need
vaccines to build up their own Active
Immunity.
Disease-Causing Organisms
• Bacteria- Tetanus, strep throat, and
pneumonia.
• Virus- A small piece of DNA surrounded by
a protein coat.
• A virus “Tricks” your cells into making more
viruses.
• Can cause the flu, AIDS, measles, mumps
and chickenpox.
Disease-Causing Organisms
• Protist – Malaria is spread by
mosquitoes and African
Sleeping Sickness is spread by
Tsetse fly.
• Fungi – Ringworm and
Athletes foot.
Infectious Disease
• Any disease that is caused by a virus,
bacterium, protist or fungus and is easily spread.
• Infectious Disease can be spread by contact,
water, air or food.
• Biological Vector- Any organism that is carrying
the disease.
Infectious
Disease
Bacteria
Strep
Throat
Viruses
Pneumonia
AIDS
Protists
Fungi
Ringworm
Athletes
Foot
Chickenpox
Malaria
Sleeping
Sickness