Disease
Pages 329-343
Disease
Does not allow the body to
function normally
Can affect individual organs
or an entire body system
Divided into two groups –
infectious and non-infectious
Infectious Disease
A disease that can be passed
from organism to organism
Caused by tiny organisms
called PATHOGENS
4 KINDS OF
PATHOGENS
Bacteria
Viruses
Fungi
Protist
Pathogens can come
from
Another person
Contaminated objects
Animal bite
Environment
Immune System
responsible for
distinguishing (telling the
difference) between the
different kinds of pathogens
Reacting to each kind
according to its type
When a pathogen
enters the body
It works by damaging
individual cells within the
organs
In some cases it attacks an
entire body system
Some Infectious
Diseases You Should
Know
Colds
Flu
Strep Throat
Athlete’s Foot
AIDS
Colds
Illness caused by a viral infection
located in the respiratory system
The cold virus multiplies and attacks
the mucous membranes of the nose
and throat causing the common
effects of the cold (sore throat, runny
nose, fever…)
Cold can not be treated with an
antibiotic because it is caused by a
virus
Flu
Influenza, commonly known as
“the flu”, is a highly contagious
viral disease of the respiratory
system
Typically causes fever, muscle
aches, and a more severe cough
than the common cold and
usually lasts longer
Athlete’s foot
Common fungal infection of the
skin of the feet
May be contracted from public
environments
Grows in the warm and moist
environment usually between the
toes
Difficult to cure
AIDS
Acquired immunodeficiency
syndrome (AIDS)
Caused by the human
immunodeficiency virus (HIV)
The virus attacks the cells in the
immune system making the
organism unable to fight off other
pathogens that may attack the
body
Strep Throat
Contagious disease caused by
bacterial infection
Symptoms include fever, pain,
redness and swelling of the
throat and tonsils
May produce mild or severe
symptoms
Let’s follow the
journey of a
pathogen as it
attacks its victim!
What type of pathogen is
Salmonella?
Salmonella
is a bacterium
What was the source
of the pathogen?
Source of the pathogen
Contaminated food
What is the first
defense?
Stomach acid destroys some
of the bacteria
Macrophages try to destroy
the Salmonella
What does the body
do next to try and get
rid of the pathogen?
How does Salmonella
attack the body?
Enters the cells of the villi and
destroys them
The destroyed cells release
distress chemicals
What causes the diarrhea?
The waves of peristalsis are so
rapid that the large intestine is
unable to absorb the water
How does Salmonella
cause your body to
ache?
The chemicals released from
the cells leak into the blood
stream and go into the
muscle tissue
Does the medicine
kill the Salmonella?
How does the
immune system
begin to respond to
the Salmonella
invasion?
The immune system identifies
the pathogen and produces
helper cells
Helper cells “help” the
macrophages to do their job –
destroy the Salmonella
Non-infectious
Diseases
Not caused by pathogens in
the body
Not spread from organism to
organism
Non-infectious Diseases
are caused by
malfunctions in the body.
Heredity – information you get
from your parents
The environment – examples
are sun, radiation, chemicals
Lifestyle choices – smoking,
drugs, alcohol
Types of Noninfectious
Diseases
Diabetes
Asthma
Parkinson’s disease
Skin Cancer
Diabetes
A disease that results in
glucose (sugar) level being
higher than normal.
It is caused by the person’s
inability to either produce
or use properly a natural
chemical made in the body
(pancreas) called insulin.
Diabetes may lead to
Kidney disease
Heart disease
Vision problems
High levels of blood
sugar lead to disorders
Like an increase in
problems with circulation
Parkinson’s
Disease
Disease of the nervous
system that occurs when
nerve cells in the brain stop
functioning properly, affecting
the muscular system
Parkinson’s
Disease
Major symptoms
Severe shaking (tremors)
Disabilities involving
movement
At present, there is no
cure
Skin Cancer
Disease in which skin cells
found in the outer layers of
the skin become damaged.
Factors that lead to
Skin Cancer
Damaging ultraviolet rays
(UV) from the sun or tanning
beds
heredity
Asthma
Affects the lungs and the
airways that deliver air to the
lungs
Causes periodic attacks of
wheezing and difficulty
breathing
Asthma attacks
Occur when the airways become
inflamed in response to a
stimulus, such as dust, mold,
pets, exercise, or cold weather
Some attacks start for no
apparent reason
Resources
Body Story: Germs. Discovery Channel
School. 2002.
unitedstreaming. 5 December 2006
www.a1organics.com/images/pathogens.jpg
www.monografias.com/trabajos5/virus/Image166.gif
www.uwlax.edu/.../Visuals/athletesfoot.jpg
www.ucmp.berkeley.edu/.../paramecium1.gif
www.fordogtrainers.com
moon.ouhsc.edu
www.wcasohio.org
www.kidsplanet.org
www.missouri.edu
tiee.ecoed.net
www.moea.state.mn.us
colds.upmc.com