Download Chapter 19, Section 1 Infectious Disease

Chapter 19, Section 1
Infectious Disease
Monday, April 26, 2010
Pages 592 -- 595
Objectives
• Explain the cause of infectious disease
and identify the kinds of organisms that
cause disease.
• Describe the methods in which
pathogens enter the body.
Vocabulary Words
• Pathogen
• Infectious disease
• Pasteurization
How Does a Disease Spread?
• Disease is spread through
microorganisms.
• “Let’s shake hands!”
Disease and Pathogens
• Organisms that cause disease are
called pathogens.
• Diseases caused by pathogens are
infectious.
– Can be passed from one organism to
another.
– Pathogens harm your body by damaging
individual cells.
Disease and Pathogens -cont’d
• Each infectious disease is caused by a
specific pathogen.
• There are 4 major groups of human
pathogens.
– Bacteria
– Viruses
– Fungi
– Protists
Bacterium
QuickTime™ and a
decompressor
are needed to see this picture.
• Bacterium is
unicellular.
• Strep throat is
caused by a
bacterium.
Viruses
QuickTime™ and a
decompressor
are needed to see this picture.
• Viruses are nonliving and can only
reproduce inside
living things.
• Colds and influenza
are examples of
diseases caused by
viruses.
Fungi
QuickTime™ and a
decompressor
are needed to see this picture.
• Fungi are primitive
vegetables.
• Reproduced through
tiny spores.
• Infections are caused
by the spores landing
on your skin.
• Athlete’s foot is an
example.
Protists
QuickTime™ and a
decompressor
are needed to see this picture.
• Protists are
unicellular.
• It is parasitic.
• Malaria is an
example of a
disease caused by
protists.
Pasteurization
• Process introduced
by Louis Pasteur
(soup guy).
• It’s a heating
process that is used
to kill
microorganisms.
– Juice, milk, etc.
Ways Disease Spread
• You can become infected by a pathogen
in one of several ways:
– Person to person transfer
– Contaminated objects
– Animal bites
– Pathogens from the environment
Person-to-Person Transfer
• Transfer is through
direct contact.
– Kissing, hugging,
shaking hands.
• Transfer can also be
indirect.
– Coughing, sneezing.
QuickTime™ and a
decompressor
are needed to see this picture.
Contaminated Objects
• External objects are
contaminated
because some
pathogens can live
for a short time
outside a person’s
body.
– Food, water, other
objects.
QuickTime™ and a
decompressor
are needed to see this picture.
Animal Bites
• Infected animals can
pass on pathogens
when they bite
another animal or
person.
– Rabies, Lyme
Disease, Malaria
QuickTime™ and a
decompressor
are needed to see this picture.
Pathogens from the
Environment
• Pathogens from
spores that land on
you or on the soil.
– Examples include
tetanus and
botulism.
– These toxins are
extremely powerful.
QuickTime™ and a
decompressor
are needed to see this picture.
Review
• Name the four kinds of pathogens that
cause disease in humans.
• Describe the four ways that pathogens
can infect humans.
• How did Pasteur contribute to our
understanding of infectious disease.
Homework
• Workbook 19.1 (4/27)
• Vocabulary quiz 19.1 (4/27)