Download Chapter 13- Infectious Diseases

Chapter 13- Infectious
Diseases
Section 1- What are Infectious Diseases?
Section 2- Protecting Yourself from Infectious
Diseases
Section 3- Common Infectious Diseases
Objectives for Chapter 13
Identify different agents that cause infectious
diseases
List four ways infectious diseases spread
Describe different treatments for infectious
diseases
Describe how the body fights infectious diseases
Summarize five things a person can do to stay
well
Objectives cont.
Describe how immunity to a disease
develops
State three things you should do when you
are sick
List three things you can do to prevent the
spread of infectious diseases
Infectious Diseases
An infectious disease is any disease that
is caused by an agent that has invaded
the body.
Examples of infectious diseases: colds,
the flu, head lice, and tuberculosis
All infectious diseases are caused by
pathogens
A pathogen is any agent that causes
disease.
Bacteria
Tiny, single-celled organisms
Most bacteria are harmless, many are
actually helpful
Some bacteria make you sick when they
grow inside your body
Some bacteria give off poisons, while
other bacteria enter and damage cells
Tuberculosis, tetanus, and sinus infections
Viruses
Smaller than bacteria
Tiny, disease-causing particles made up of
genetic material and a protein coat
The genetic material contains instructions
for making more viruses
Viruses survive and replicate only inside
living cells
Chicken pox, colds, the flu, measles, and
HIV
Fungi
An organism that absorbs and uses the
nutrients of living or dead organisms
Athlete’s foot- caused by a fungus that
lives and feeds on your feet and makes
them burn and itch
Ringworm- a fungus responsible for a
scaly, circular rash
Protozoans
Single-celled, microscopic organisms that
are larger and more internally complex
than bacteria
Protozoans account for diseases that are
the leading causes of death throughout
some parts of the world
Malaria is a disease caused by protozoans
Parasites
Animal parasites get their energy and
nutrients by feeding on other living things
Examples of harmful animal parasites
include head lice, tapeworms, and certain
roundworms
Bacteria
Viruses
Fungi
Protozoans
Parasites
How are Infectious Diseases
Spread?
Person-to-person- through the air or contact with
another person
examples: flu, colds, measles
Food-and-water- through the food you eat or the
water you drink.
examples: hepatitis A, botulism, typhoid, cholera
Environment- from the objects around you
example: tetanus
Animals- from animals or insects
examples: ringworm, malaria, Lyme disease
Treating Infectious Diseases
Bacterial diseases- antibiotics
Viral diseases- most medications rely on
relieving symptoms and stopping the
production of viruses inside the human
cells
Fungal infections- over-the-counter
antifungal medicine
Protozoan infections- prevention is the key
Parasitic infections- medications
Protecting Yourself from
Infectious Diseases
Chapter 13 Section 2
How Your Body Fights Disease
Your body’s first line of defense includes your
skin, mucous membranes, and chemicals.
Skin keeps pathogens from entering your body
Mucous membranes, such as your nose, mouth,
and throat, trap pathogens and move them to
your stomach to be destroyed.
Your sweat, tears, and stomach acid are all
chemicals that kill bacteria
Inflammatory Response
Your body’s second line of defense is
inflammation.
Inflammation- a reaction to injury or infection that
is characterized by pain, redness, or swelling.
This is caused by the small blood vessels that
expand to bring more blood to the injured area
This response shows that your body is attacking
pathogens
Immune System
This is your third line of defense
The immune system is made up of certain
types of blood cells and certain proteins
called antibodies.
These infection-fighting cells move
through the lymphatic system, a network
of vessels that carry a clear fluid called
lymph throughout the body.
White blood cells are cells in the blood
whose primary job is to defend the body
against disease.
When you are sick, your lymph nodes
often swell because of the growing
number of white blood cells fighting the
infection.
Active immunity is established when the
body produces antibodies that recognize
future pathogens (either by having the
disease or by vaccination)
What You Can Do to Stay Well
Protect yourself
Eat a healthy, balanced diet
Drink water
Reduce your stress levels
Exercise regularly
Get regular medical checkups
Try to avoid close contact with sick people
Get enough sleep
Get Vaccinated
Vaccines are substances usually prepared from
killed or weakened pathogens or from genetic
material and that is introduced into a body to
produce immunity.
When a vaccine is injected, the immune system
responds by making white blood cells called
memory cells.
In the future, if the pathogen enters the body, the
memory cells and their antibodies fight the
pathogen before it can cause disease.
What to Do When You Are Sick
Stay home
Get plenty of rest
Try not to pass your illness to others
Don’t share personal items
Cover your mouth
Drink plenty of fluids
See a doctor and take the doctor’s advice
Take medications that are prescribed to you
Wash your hands frequently