Download Lesson 1 Infectious Diseases

Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
Lesson 1
Infectious
Diseases
pages 548-551
Identify the causes of infectious diseases.
Describe four ways in which infectious
diseases are spread.
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
Causes of Infectious Diseases
Communicable diseases caused by organisms or
viruses that enter and multiply within the body.
Viruses that can only be seen through a
microscope are called microorganisms.
Pathogens (Germs) – microorganisms and
viruses that cause disease, make you sick.
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
Types of Pathogens (Germs)
Bacteria – simple, single-celled microorganism.
Give off toxins (poisons).
Examples of illness caused by bacteria: tetanus, food poisoning,
strep throat, TB, staph infection
Viruses – smallest pathogen. Enters a healthy cell
and then damages or destroys that cell. Viruses
are specific as to the body systems they attack.
Examples of body systems attacked and the diseases caused by
viruses: Respiratory-common cold, influenza; Immune-hepatitis,
AIDS; Skin-chickenpox, rubella, measles; Nervous-rabies, polio
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
More Types of Pathogens
(Germs)
Fungi – grow best in warm, dark moist areas.
Usually causes skin infections.
Examples of skin infections caused by fungi: athlete’s foot,
ringworm, infected scalp
Protozoans – single celled organism, larger
than a bacteria. Usually found in contaminated
water.
Examples of sickness caused by Protozoans:
Amebic Dysentery (bloody diarrhea), Dysentery
(stomach pain, diarrhea) Malaria,
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
More Types of Pathogens (Germs)
Other Pathogens – reside in insects (lice, mites)
and in under cooked meat (particularly pork).
List 3 facts for each of the four major types of
Pathogens…
1. Bacteria
2. Viruses
3. Fungi
4. Protozoans
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
How Pathogens
(Germs) are Spread:
Pathogens enter the body through breaks in
the skin, direct contact with pathogen and
eyes, ears, nose and mouth.
Infected People – skin to skin, direct contact
with infection spreads the pathogens (cold
sores, chicken pox, sexually transmitted
diseases…), and by breathing in the airborne
pathogens (infected person coughs or sneezes),
contact with infected person’s body fluid and
blood.
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
How Pathogens (Germs) are Spread:
Contaminated Food, Soil or Water – Bacteria
naturally live in food and soil.
Bacteria that can make you sick:
Salmonella – lives in poultry and eggs, found in
feces droppings from birds or mice
E. coli – lives in beef
Botulism – improperly canned food
Tetanus – found in soil and rust
Cholera – contaminated water
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
REVIEW Chp. 21 Lesson 1
In what ways can you protect
yourself from getting sick?
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
Lesson 3
Common Infectious
Diseases
pages 558-563
Identify some diseases caused by bacteria
and by viruses.
Describe behaviors that can help you get
healthy and stay healthy.
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
Bacteria Diseases
Strep Throat – Streptococcus. Spread by mucus
of infected person.
Symptoms: swollen lymph nodes on sides of neck, fever,
headache, fever, sore throat
Lyme Disease – Spread by bite from infected tick.
Symptoms: red rash at site of bite, fever, chills, and body aches
Bacterial Meningitis– Fluid that surrounds spinal cord and
brain that becomes infected.
Symptoms: high fever, headache, vomiting and a stiff neck
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
More Bacteria Diseases
Tuberculosis – highly contagious infection of the
lungs. Transmitted from inhaling droplets from an
infected person’s cough or sneeze.
Symptoms: fatigue, weight loss, a mild fever, constant cough
Treating Bacterial Diseases – Antibiotics are a
prescription medicine that must be used as
prescribed. Bacteria can develop a resistance to
the antibiotics, making it difficult to treat certain
diseases.
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
Viral Diseases
The Common Cold – There is no cure; caused by
different viruses. Spread by contaminated objects
and airborne pathogens
Symptoms: sneezing, sore throats, runny noses, coughing, fever,
headaches, chest congestion and muscle aches
Influenza – Affects respiratory system spread by
airborne pathogens and contaminated objects;
more serious than cold viruses. Vaccines can
prevented by flu shots.
Symptoms: high fever, sore throat, headache and a cough
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
Viral Diseases
Hepatitis – Infects the liver.
Symptoms: fever, nausea, pain in abdomen and jaundice
Hepatitis A – transmitted in human wastes and in
contaminated food and water. A vaccine can prevent Hepatitis A
Hepatitis B – transmitted in blood or sexual contact or
body piercing/tattoos. There is a vaccine for Hepatitis B
Hepatitis C – transmitted in blood or sexual contact
or body piercing/tattoos. Number one reason for liver
transplants.
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
Viral Diseases
Treating Viral Diseases –
Usual there is no medicine
that can cure a viral infection,
medicines only treat the
symptoms of the diseases. Rest,
a well-balanced diet and plenty
of fluids help to shorten the life
of some viruses in the body.
See pages 560-561, Illustration of the
stages of the Flu
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
Getting Healthy, Stay Healthy
When to Seek Medical Care: Extremely sore
throat, earache, temperature, vomiting, diarrhea
that lasts more than 2 days; yellow/green thick
mucus from nose or throat; difficulty breathing or
severe pain anywhere; a wound that does not heal;
an illness that lasts longer than usual
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Chapter 21
Infectious Diseases
Practicing Healthful Behaviors
Getting Healthy, Stay Healthy
Preventing Infectious Diseases: Avoid contact with
pathogens, be immunized, choose healthy behaviors…
Frequently wash hands; do not share items; cook/store foods
properly; avoid sick people; sneeze into elbow; eat healthy;
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avoid unhealthy substances
Chapter 21
Infectious Diseases
REVIEW Chp. 21 Lesson
Practicing Healthful Behaviors
In what ways can students
minimize the spread of
pathogens at school?
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