Download infectious disease - What is happening in Mr. Nolan`s Health Class

Thursday, April 17 “A” Day
• Go over CPR/First Aid Review Assignment
• CPR/First Aid Written Exam
• “Understanding Infectious Diseases” reading & questions.
If it takes six men six days to dig six holes, how long will
it take one man to dig half a hole?
Answer: There is no such thing as Half a hole. A
hole is a hole.
Medic First Aid Basic Plus
Adult Cpr/First Aid Test
• DO NOT write on the test.
• Using a #2 pencil, put your answers on the Scantron
answer sheet.
• When you are finished with the test, turn in your test
questions and answer sheet to Mr. Nolan
• Grab a Health textbook. Read pages 548-551. Take
notes on the reading.
• Answer the section review questions on the half
sheet of paper.
Section 21.1
Understanding Infectious Diseases
Objectives
Identify the causes of infectious diseases.
Describe four ways in which infectious
diseases are spread.
Myth There isn’t much a person can do to avoid spreading
or catching a cold or the flu.
Fact About 80% of infectious diseases are spread by hand
contact. Washing your hands with soap and water is a
simple and effective way to prevent the spread of colds and
the flu.
Do you think most teens wash their hands as
much as they should? What do you think are some ways to
encourage more frequent hand washing?
Causes of Infectious Diseases
• Also known as communicable diseases, infectious
diseases (in FEK shus) are caused by organisms or
viruses that enter and multiply within the
human body.
• Microorganisms (my kroh AWR guh niz ums) are
organisms that can be seen only through
a microscope.
• Microorganisms and viruses that cause disease are
called pathogens (PATH uh junz).
• Pathogens can cause an infectious disease when
they enter your body and multiply.
Bacteria
• Bacteria (bak TEER ee uh) are
simple, single-celled microorganisms.
Bacteria live in air, soil, food, and in
and on the bodies of plants and
animals, including you.
• Some bacteria injure cells by giving off
poisons called toxins (TAHK sinz).
Cell Phone Bacteria
Jake Finkbonner
Viruses
• The smallest pathogens are viruses.
• A virus can multiply only after
entering a living cell.
• The virus then takes over the cell’s
reproductive mechanisms, resulting
in cell damage or death.
How a virus invades your body VIDEO
Fungi
• Organisms such as yeasts,
molds, and mushrooms are
known as fungi (FUN jy).
• Fungi grow best in warm, dark,
moist areas.
Protozoans
• Single-celled organisms that
are much larger and more
complex than bacteria are
known as protozoans
(proh tuh ZOH unz).
• Protozoans have the ability to
move through fluids in search
of food.
Malaria Video
Other Pathogens
Some infectious diseases are caused by animals such
as mites, lice, and certain worms.
How Pathogens Are Spread
• Pathogens can spread through contact with
• an infected person
• an infected animal
• contaminated objects
• contaminated food
• contaminated soil
• contaminated water
• The pathogens can then enter the body through
breaks in the skin or through the moist linings of the
eyes, ears, nose, mouth, or other openings.
Infected People
• Many infectious diseases are spread through some
form of contact with a person who has the disease.
• The contact may be direct physical contact.
• Infectious diseases
can also spread
through indirect
contact.
Infected Animals
Some infectious diseases are
transmitted to humans through
the bites of animals.
Contaminated Objects
• Some pathogens can survive for a period of time
outside a person’s body.
• These pathogens can be spread from person to
person on objects such as
• doorknobs
• eating utensils
• towels
• needles used for
body piercings
and tattoos
Contaminated Food, Soil, or Water
• Some pathogens are naturally
present in food and soil.
• Sometimes water and food
become contaminated with
pathogens from infected people.
Vocabulary
infectious
disease
microorganism
pathogen
bacteria
A disease caused by an organism or virus that
enters and multiplies within the human body.
An organism that is so small it can only be seen
through a microscope.
A microorganism or virus that causes disease.
Simple, single-celled microorganisms.
toxin
A poison given off by some bacteria that can
injure cells.
virus
The smallest type of pathogen.
Vocabulary
fungi
protozoan
Organisms such as yeasts, molds, and
mushrooms that grow best in warm, dark,
moist areas.
A large and complex single-celled organism.
Section 1 Review Questions
Key Ideas and Vocabulary
1. What is a pathogen? Name four types of pathogens.
A pathogen is a microorganism or virus that causes disease. Four
types are bacteria, viruses, fungi, and protozoans.
•
2. How do pathogens cause infectious diseases?
Pathogens can cause an infectious disease when they enter the
body and multiply.
•
•
3. What is a virus? How are viruses different from
bacteria?
A virus is the smallest kind of pathogen. Unlike most bacteria, a virus
can multiply only after entering a living cell.
Section 1 Review Questions
4. What are four ways that infectious diseases can
spread?
Infectious diseases can spread through contact with an infected person,
an infected animal, contaminated objects, and contaminated food,
soil, or water.
5. Applying Concepts If you were traveling to a country where mosquito-borne
diseases were common, how would you protect yourself from getting infected?
Sample answer: by applying mosquito repellent, by wearing long
sleeves and long pants, and by staying indoors during times when
mosquitoes are most active
6. Relating Cause and Effect Why do you think that communities boil their drinking
water after a water line break?
Sample answer: A water line break can allow harmful bacteria to enter
the water supply. Boiling contaminated water kills most or all of the
harmful bacteria.
Write the letter of the correct answer using
the list on the right.
1. Organisms such as yeasts, molds, and
mushrooms.__________
2. Single-celled organisms that are much
larger and more complex than
bacteria. __________
3. Simple, single-celled microorganisms.
________
4. Microorganisms and viruses that
cause disease. _______
5. The smallest pathogens._______
a.
b.
c.
d.
e.
f.
Pathogens
Bacteria
Toxins
Fungi
Protozoan
Viruses
Decide whether each statement is true or false.
6. Some infectious diseases are transmitted to humans through the
bites of animals. _________
7. An infected person cannot spread a disease to another person.
_______
8. Pathogens can cause an infectious disease when they enter your
body and multiply. ________
9. It is important to refrigerate food promptly to prevent the growth of
harmful bacteria. ________
10. All pathogens die immediately when they leave a person’s
body.________
Section 21.2
Defenses Against Disease
Objectives
Identify the body’s physical and chemical
defenses against infectious disease.
Describe the inflammatory response.
Summarize how the immune system works.
Compare passive and active immunity.
Section 21.2 Defenses Against Disease
VIDEO
• Protection from Infection
Slide
26 of
28
Quick Quiz Complete each of these statements with always,
sometimes, or never.
I ____ wash my hands before meals.
When preparing fruits and vegetables, I ____ wash
them thoroughly.
I am ____ careful to use only my own eating utensils,
drinking cups, towels and grooming items.
I ____ cover my mouth when I cough or sneeze.
If I spend time in wooded areas, I ____ wear
insect repellent.
For each of your responses, explain how your behavior
could affect your chances of getting or spreading an
infectious disease.
Physical and Chemical
Defenses
Your body’s first line of defense against infectious
disease includes both physical and chemical defenses
that prevent pathogens from entering your body.
Skin
• Your skin serves as both a physical and a chemical
barrier against pathogens.
• Sweat acts as a chemical barrier.
• Old skin cells are shed constantly, and the
pathogens on these cells are shed, too.
Mucous Membranes
• The openings into your body, such as your mouth,
eyes, and nose, are covered by protective linings
called mucous membranes (MYOO kus).
• Mucus traps many pathogens and washes
them away.
• Mucus contains chemicals and specialized cells that
attack pathogens.
Cilia
• Some of your body’s mucous membranes are lined
with tiny hairlike structures called cilia (SIL ee uh).
• Together, cilia and mucus help trap and
remove pathogens.
Saliva and Tears
• Your saliva and tears can trap pathogens and wash
them away.
• Saliva and tears also contain chemicals that attack
pathogens.
Digestive System
• Chemicals in your digestive system kill
many pathogens.
• The normal motions of the digestive system move
pathogens out.
• Bacteria that normally live in your digestive system
produce substances that can harm or kill
invading bacteria.
Your Body’s Physical and Chemical Defenses
5)
1)
2)
3)
4)
Stomach
Saliva andacid
tears
When
certain
Saliva you
and swallow
tears can
wash pathogens
with
water,
or mucus, acids in your
awayfood,
some
pathogens.
stomach can kill those pathogens.
1
Mucous membranes
Mucus traps some pathogens,
preventing them from entering
your body.
Cilia
Cilia help move mucus
and pathogens out of
your body when you
cough or sneeze.
Skin
Your skin is an effective barrier
against many pathogens.
2
3
4
5
Inflammation
• Inflammation (in fluh MAY shun) is your body’s
general response to all kinds of injury, from cuts and
scrapes to internal damage.
• Inflammation fights infection and promotes the
healing process.
Phagocytes
• Within seconds after your body is injured, the
damaged cells release chemicals that cause blood
vessels in the injured area to enlarge.
• Blood, other fluids, and white blood cells called
phagocytes (FAG uh syts) leak out of the
enlarged vessels.
• Phagocytes engulf and destroy pathogens.
Phagocytes
This micrograph shows a phagocyte (blue) attacking
bacteria (pink). Phagocytes kill pathogens by
engulfing and then digesting them.
Healing
• Phagocytes also give off substances that cause
healing to begin.
• The inflammation process heals the damage, and the
inflammation subsides.
The Immune System
The immune system (ih MYOON) fights disease by
producing a separate set of weapons for each kind of
pathogen it encounters.
The Immune Response
• When a pathogen enters your body for the first time,
it often causes disease.
• White blood cells called lymphocytes (LIM fuh syts)
carry out most of the immune system’s functions.
• If a pathogen that has previously attacked your body
enters your body again your immune system will
quickly recognize the pathogen and launch an
immediate attack.
• Immunity (ih MYOON ih tee) is your body’s ability to
destroy pathogens that it has previously encountered
before the pathogens are able to cause disease.
T Cells
T cells perform several functions.
• Killer T cells destroy any body cell that has been
infected by a pathogen.
• Helper T cells produce chemicals that stimulate
other T cells and B cells to fight off infection.
• Suppressor T cells produce chemicals that “turn
off” other immune system cells when an infection
has been brought under control.
B Cells
• The B lymphocytes, or B cells, produce antibodies.
• Antibodies (AN tih bahd eez) are proteins that
attach to the surface of pathogens or to the toxins
produced by pathogens.
• This binding action keeps the pathogen or toxin from
harming the body.
• The memory capacity of B cells explains why you
develop immunity to some diseases you’ve already
had.
The Immune Response
The Lymphatic System
• The lymphatic system (lim FAT ik) is a network of
vessels that collects fluid from your tissues and
returns it to the bloodstream.
• The fluid flowing through the lymphatic system is
called lymph (limf).
• The lymphatic vessels have hundreds of small
stations, called lymph nodes.
The Lymphatic System
Your lymphatic system is a
complex network of vessels
and nodes.
Lymph
nodes
Lymph
vessel
Passive and Active Immunity
Passive Immunity
• Immunity acquired by receiving antibodies from a
source other than one’s own immune system is
called passive immunity.
• This type of immunity is temporary, not lifelong.
• It occurs naturally in babies, who receive antibodies
from their mothers before birth.
• Passive immunity can be artificially acquired.
Passive and Active
Immunity
Active Immunity
• Active immunity results from either having a disease
or from receiving a vaccine.
• Injections, which cause you to become immune to a
disease, are called immunizations
(im yuh nih ZAY shunz), or vaccinations.
• The substance that is injected is called a
vaccine (vak SEEN).
• Vaccines contain small amounts of dead or modified
pathogens or their toxins.
Your Immune System: Natural
Born Killer
• http://www.youtube.com/watch?v=CeVtPDjJBPU&f
eature=plcp
Vocabulary
mucous
membrane
inflammation
phagocyte
immune system
lymphocyte
The protective lining that covers any opening
into the body.
The body’s general response to all kinds
of injury.
A type of white blood cell that engulfs and
destroys pathogens.
The body’s most sophisticated defense
against pathogens.
A type of white blood cell that carries out
functions of the immune system.
Vocabulary
immunity
The body’s ability to destroy a pathogen that it
has previously encountered before the pathogen
is able to cause disease.
T cell
A type of lymphocyte that helps the immune
system destroy pathogens.
B cell
A lymphocyte that produces antibodies.
antibody
A protein that attaches to the surface of
pathogens or to the toxins produced by
pathogens, keeping the pathogen or toxin from
harming the body.
Vocabulary
lymphatic
system
immunization
vaccine
A network of vessels that collects fluid from
body tissues and returns it to the bloodstream;
contains much of the immune system.
An injection that causes the body to become
immune to an infectious disease; also called
a vaccination.
A substance containing small amounts of dead
or modified pathogens or their toxins that is
injected during an immunization.
Section 21.2 Defenses Against Disease
The Immune Response
Review
With your group, answer the following
questions on a piece of paper. Put
your group member names on the top
of the page.
1.) Describe what happens when a
pathogen, such as a virus, first enters
the body.
2.) What role do killer T cells play in the
immune response?
3.) What are antibodies? What kinds of
cells produce antibodies?
4.) Describe how antibodies fight
pathogens. To how many kinds of
pathogens can each antibody attach?
5.) Within which system of the body
does the immune response occur?
Describe this body system.
6.) Usually people can only develop a
viral disease such as chicken pox
once in their lives. Explain the role of
antibodies in this immunity.
The Immune Response
Answers
1.) A T cell recognizes the virus. The T
cell divides over and over, producing
new T cells that also recognize the
virus.
2.) Killer T cells attack any cells that
have been infected by a pathogen.
They destroy the cells and the
pathogen.
3.) Antibodies are proteins that attach
to the surface of pathogens or to the
toxins produced by pathogens. B cells
(B lymphocytes) produce antibodies.
4.) Antibodies bind to pathogens,
which then clump together and are
destroyed by phagocytes. Each
antibody can attack only one specific
pathogen.
5.) The lymphatic system; a network of
vessels and nodes that collects fluid
from body tissues and returns it to the
bloodstream.
6.) After the viral infection is overcome,
the B cells stop producing antibodies
to the chicken pox virus, but they do
not “forget” how to produce them.
Those B cells circulate in the body for
years, ready to produce antibodies
quickly if the same pathogen reenters
the body.
Section 21.3
21.2 Defenses Against Disease
Common Infectious Diseases
Objectives
Identify some diseases caused by bacteria and
by viruses.
Describe behaviors that can help you get
healthy and stay healthy.
Slide 56 of 26
Section 21.2 Defenses Against Disease
Lyme Disease
• Humans can become infected with the bacteria that
cause Lyme disease when they are bitten by an
infected tick.
• Symptoms of Lyme disease include
• a red rash at the site of the tick bite
• fever
• chills
• body aches
• The best way to protect yourself from Lyme disease
is by avoiding tick bites.
Bacterial Meningitis
• An infection of the fluid in the spinal cord and the
fluid that surrounds the brain is called meningitis.
• Symptoms of meningitis include high fever,
headache, vomiting, and a stiff neck.
• There are two types of meningitis—one is caused by
bacteria, the other by a virus.
Tuberculosis
• A highly contagious bacterial infection of the lungs is
tuberculosis (too bur kyuh LOH sis), or TB.
• It is transmitted when droplets from an infected
person’s cough or sneeze are inhaled.
• Symptoms, which include fatigue, weight loss, a mild
fever, and a constant cough, may not show up for
many years after the initial infection.
Treating Bacterial Diseases
• An antibiotic (an tih by AHT ik) is a drug that inhibits
or kills bacteria.
• Using antibiotics exactly as they are prescribed is
very important to prevent bacteria from developing
resistance to the medicine.
• Antibiotic resistance can result if you don’t finish your
prescription and some of the bacterial pathogens in
your body survive.
Viral Diseases
Viral diseases include
• the common cold
• influenza
• pneumonia
• hepatitis
The Common Cold
• The common cold is really a group of symptoms that is caused
by a number of different viruses.
• One or two days after exposure to a cold virus, people develop
• sneezing
• sore throats
• runny noses
• coughing
• chest congestion
• fever
• headaches
• muscle aches
• Colds spread when a person touches a contaminated object or
inhales droplets from a sneeze or a cough.
Influenza
• The flu, or influenza, is a common viral infection of
the upper respiratory system.
• Influenza is spread by airborne droplets and contact
with contaminated objects.
• High fever, sore throat, headache, and a cough are
typical symptoms of the flu.
The Stages of the Flu
Hepatitis
• A group of viruses that infect the liver can cause hepatitis
(hep uh TY tis), or inflammation of the liver.
• Symptoms of hepatitis include
• fever
• nausea
• pain in the abdomen
• jaundice (JAWN dis), or yellowing of the skin.
• Hepatitis A is transmitted in human wastes and in
contaminated water and food.
• Hepatitis B can be transmitted in blood, during sexual
contact, or during tattooing or body piercing.
• Hepatitis C can be transmitted in blood, during sexual
contact, or during tattooing or body piercing.
Treating Viral Diseases
• In most cases, there is no particular medicine that
can cure a viral infection.
• The best treatments for viral infections are rest, a
well-balanced diet, and plenty of fluids.
• Many over-the-counter medicines can treat the
symptoms of viral infections.
Getting Healthy, Staying
Healthy
• When you do get sick, you can help your body
recover by going to bed and resting.
• This treatment and well-balanced meals are all that
you need to recover from most mild infections.
When to Seek Medical Care
• If you are worried about your health for any reason, see a
doctor and discuss your concerns with him
or her.
• Seek professional medical care if you have
• an extremely sore throat, earache, vomiting, diarrhea,
or a temperature of 101°F that lasts more than two
days
• mucus from your nose or throat that is thick and
yellowish green
• difficulty breathing, or severe pain anywhere
• a cut, scrape, or sore that does not seem to be
healing as it should
• an illness that lasts longer than usual
Preventing Infectious Diseases
You can protect yourself from infectious diseases in
three ways
• avoiding contact with pathogens
• making sure that your immunizations are current
• choosing healthful behaviors
Preventing Infectious Diseases
Here are some healthful behaviors you should
practice to help you avoid disease.
• Wash your hands several times a day, especially
before eating and after using the bathroom.
• Do not share items that can transfer pathogens,
such as towels, eating utensils, cups,
or hairbrushes.
• Cook and store foods properly. Meats should be
cooked thoroughly. Hot foods should be kept hot,
and cold foods should be kept cold.
• Avoid close contact with people who are ill.
Preventing Infectious Diseases
Here are some healthful behaviors you should
practice to help you avoid disease.
• Stay home when you are not feeling well.
• Learn to manage stress in healthful ways, and
get at least eight hours of sleep each night.
• Eat well-balanced meals, and do not skip meals.
Exercise regularly, at least three or more times a
week.
• Avoid unhealthful substances, such as tobacco,
alcohol, and illegal drugs.
Section 21.4
Emerging Infectious Diseases
Objectives
Define the term emerging disease.
Identify five reasons why diseases emerge.
Health Stats The map shows how dengue fever, a viral disease carried
by mosquitoes, has spread since 1960.
Should the United States be concerned about dengue
fever? Explain.
What Is an Emerging Disease?
• An epidemic (ep uh DEM ik) is an unusually high
occurrence of a disease in a certain place during a
certain time period.
• When an epidemic affects many areas of the world, it
is sometimes called a pandemic.
• An emerging disease is an infectious disease that
has become increasingly common in humans within
the last 20 years or threatens to become more
common in the near future.
Why Do Diseases Emerge?
• Diseases can emerge when humans come into
contact with infected animals; pathogens become
resistant to existing drugs; or people lack
appropriate immunizations.
• The increased frequency of international travel and a
global food supply can enable emerging diseases to
spread very quickly.
Contact With Infected Animals
• Some diseases that are common in animals can
spread to humans.
• There have been recent cases in Asia in which
people have become sick after being exposed to
infected birds.
• Scientists fear that another deadly flu epidemic could
result if the virus takes on a form that can spread
easily between people.
http://abcnews.go.com/Nightline/video/west-nile-virusfighting-deadly-outbreak-17277245
Drug Resistance
• Some diseases are caused by pathogens that can
mutate, or change, over time.
• Sometimes these mutations result in a strain, or type,
of pathogen that no longer responds to medicine.
Lack of Immunization
• Diseases that were common many years ago can
pose a threat again if people don’t get the
proper immunizations.
• The polio virus remains a threat in several Asian and
African countries because many people in those
countries have not received the vaccine.
International Travel
• Globalization refers to the fact that people around the
world are no longer geographically isolated from
each other.
• Not only can people travel much more easily, but so
can any pathogens that live in their bodies.
• World travelers could spread the pathogen around
the world in a short amount of time.
http://www.youtube.com/watch?v=aE69K_lP2ug
Ebola
Global Food Supply
• Food also travels around the world.
• If a pathogen is present in a food product, it can
spread quickly.