Immunity From Disease Chapter 17 - PowerPoint Presentation

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Immunity From Disease

Chapter 17Slide2

disease

Disease-any condition that impairs the normal functioning of the body

Violation of homeostasis

Homeostasis-ability of the body to keep proper internal conditions no matter what is happening outside of it

Can be infectious or non-infectious

Infectious diseases are typically caused by pathogens (disease causing agents)

Bacteria,

protists

, fungi, viruses, prions, worms, etc.

Non-infectious diseases are usually the result of errors within the body

Cancer, heart disease, etc.

The line between the two is blurry

Some infectious agents can lead to non-infectious diseases

Viruses can alter the cell cycle and lead to cancerSlide3

Noninfectious Disease

Disease that does not pass from person to person

Can be genetic, environmental, or a combination of the two

Examples:

Sickle Cell Anemia-Hereditary

Osteoporosis-Hereditary and Environmental (poor diet)

Diabetes-Hereditary and dietary

Cancer-Hereditary, environmental and can be infections (HPV (aka genital warts) can increase chance of cervical cancer)Slide4

Edward jenner

Father of Immunology

Developed the first vaccine in 1796

Smallpox was killing millions of people

Injected cowpox, a less harmful yet related disease, into a child

Then injected that child with smallpox

The child did not get infected

Others began using this methodSaved many livesSlide5

John Snow

One of the first to study epidemiology

Study of patterns, causes, and effects of diseases in populations

Studied Cholera spread in London, England during 1854

Cholera is an intestinal disease that causes diarrhea, and can kill with dehydration

Killed nearly 500 people in a certain area of London in a 2-week period

Snow Was able to trace the cause to contaminated water

Initially, people thought that only air carried disease, and that not much could be done He convinced the city to have the pump closed

 stopped infections in the areaSlide6

The germ theory of disease

People once thought that spirits caused disease

Holes were drilled in infected people’s heads in an attempt to release the evil spirits

In 1857, French scientist louis Pasteur made the connection between microorganisms and disease

He hypothesized that the disease could be eliminated if the organism was eliminated

Discovered that bacteria could be killed by boiling them

Called pasteurization

A food is heated to a temperature that kills most harmful bacteriaSlide7

Joseph lister

1865

British surgeon

Noticed that about ½ of his patients died from infections, even after successful surgery

Heard about Pasteur’s theory and began doing something drastic

Washing his hands…

The number of infections dropped dramatically (nearly 0)

He also discovered that bacteria can be killed using acidsDeveloped the first disinfecting sprayListerine is named after himSlide8

Robert Koch

1883

German physician

Found that he could make organisms sick by injecting it with pathogens from a sick animal

Came up with 4 conditions that must be met before one can conclude that that a certain pathogen causes a disease

Called Koch’s postulates Slide9

Koch’s postulates

The pathogen must be found in every case the disease is found

The pathogen must be isolated and grown in a pure culture

Healthy organisms infected with the culture must develop the disease

The pathogen must be isolated from the second organism and found to be identical to the firstSlide10
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infectious diseases

Any disease caused by the presence of pathogens in the body

Can be transmitted to others

Contagious-Disease that spreads from one organism to another through close proximity

Does not even require contact

COMMUNICABLE-DISEASE THAT CAN SPREAD FROM PERSON TO PERSON, BUT NOT USUALLY SPREAD THROUGH EVERYDAY CONTACT

Example: herpes Slide12

Spread of infectious diseases

The main source of human pathogens is the human body itself

Carriers-someone who passes the illness on without being infected themselves

Some diseases can be transmitted by other species

Zoonotic diseases

Other diseases can be found in the environment

Dirt, water, etc.Slide13

Transmission of disease

Can be transmitted 4 ways

By direct contact

By an object

Through the air

By an intermediate organism

Called a vectorSlide14

Common Disease-Causing Organisms

Viruses

Cause AIDS, flu, colds, herpes (cold sores and genital)

Bacteria

Cause ear infections, strep throat, pertussis, pneumonia, and many more

Fungi

Cause ringworm/athlete’s foot, and yeast infections including thrush

ProtistsCause malaria (vector: mosquito), African sleeping sickness (vector: fly), toxoplasmosis (vector: cat)

Prions (Infections Proteins)

Cause Bovine Spongiform Encephalopathy (Mad Cow Disease) and its human infection, Creutzfeldt-Jakob Disease Slide15
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First-Line Defenses

of the immune System

Skin, hair, mucus prevent the pathogen from entering

Respiratory system is lined with ciliated cells that can “sweep” pathogen out

Digestive system is acidic and can kill many pathogens

Circulatory system moves pathogens to organs to destroy them, and sends in specialized cells to fight infection (second-line defenders)

Nervous system can raise your body temperature to kill bacteria (fever)Slide17
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Second Line Defenses

of the Immune System

Necessary when pathogens get past the first line of defense

White blood cells “eat” (phagocytize) pathogens, or release chemicals to kill them

Inflammation occurs

Cells release a signal that they are being damaged, which causes blood vessels to widen

Causes the redness and swelling

The bigger vessels allow more WBC to come in and fight the pathogenSlide19
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Third Line Defenses

Of the Immune System

Called specific immunity

Targets only 1 type of pathogen

Antibodies (a substance that neutralizes and kills pathogens) attach to antigens (substances that cause an immune response)

White blood cells, called phagocytes, come in an destroy the pathogen

Once antibodies are produced, they are permanent, and rapidly destroy the pathogen if it tries to enter again

This is why you cannot catch the same cold or flu twice, and why you get vaccines Slide21
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Allergic reactions

If your immune system overreacts to foreign substances (such as dust or pollen), it can release massive amounts of histamines

These cause the symptoms of allergic reactions

Sneezing, increased mucus production, redness, swelling

Your body can also mistake your own cells as foreign and attack your own tissues

Called an autoimmune disorder

arthritis

Can also attack transplanted tissuesSlide23
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Passive and active immunity

Acquired immunity can be active or passive

Passive immunity-Introduction of antibodies produced outside of your body

Antibodies can be transferred from mother to child through placenta

Injecting antibodies from other organism immune to the disease

Occurs with

antivenoms

Active immunity-Your body’s production of antibodies due to exposureCaused by exposure to antigensRecovering from an infection

Vaccines

Injecting dead, weakened, or incomplete portions of pathogens to cause an immune responseSlide25
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A bit about Cancer

Cancer is uncontrolled mitosis

Cells divide out of control

Can be hereditary (breast cancer) or due to environmental factors (lung cancer and skin cancer)

Can strike anybody, regardless of age

Treated with radiation and chemotherapy

Getting better at treating, but not able to cure yet. Hopefully soon…Slide27

Preventing infectious diseases

There are precautions you can take.

Wash your hands after using the bathroom!

With soap and water, for 30 seconds (sing your ABC’s)

Wash your hands before eating

Same rules apply

Hand sanitizer is not as good, but will do if necessary

Avoid sharing foods and beveragesEven with your closest friendsEat a well-balanced diet

Vitamins in fruits and vegetables can help fight illnessSlide28

Top Causes

of Death in the US:

Heart Disease (600,000 deaths per year)

Cancer (580,000 deaths per year)

Respiratory Disease (150,000 deaths per year)

Accidents (130,000 deaths per year)

Stroke (130,000 deaths per year)

For teens:Accidents (50% of teen deaths)Suicide (15% of all deaths)

All other causes (35% of all teen Deaths)Slide29

What can be done?

Avoid the dangers early (Now rather than later)

Heart Disease:

Do not smoke!

Eat a healthy diet (avoid obesity)

Exercise (30+ minutes per day)

Get regular checkups

CancerDo not smoke!Eat a healthy diet (eat your fruits and vegetables) Exercise

Do not tan! Take precautions when in the sun

Respiratory disease

Do not smoke!

Exercise and eat healthySlide30

continued

Accidents

Wear a seatbelt when riding in a car

Be cautions in everyday activities

Stroke

Do not Smoke!

Eat health and exerciseSlide31

For young people

Do not smoke!!!!!!! Don’t ever start. Convince others to quit. Try to limit your exposure to secondhand smoke

Start developing healthy eating habits

Exercise

If you feel depressed, talk to someone! A teacher, a parent, a counselor, anyone. Get help as soon as possible

These problems do not always go away on their own. Sometimes you need help.

Do not bully others! Treat everyone with respect. Be kind. Offer help to anyone who needs it, even of they are not your friend.

If you know someone who needs help and will not seek it, report it to an adult immediately. It is better for them to be mad at you for a bit than to lose them forever.