Transcript Immunity and Disease

Immunity and Disease
• The Immune System
• Infectious Diseases
• Noninfectious Diseases
First-Line Defenses
First-Line Defenses
• Work against harmful substances and
disease-causing organisms called
pathogens.
• Your skin (keeps pathogens out) and
respiratory (cilia-traps pathogens; mucusreleases enzymes that weaken
pathogens), digestive (enzymes, acids,
and mucus), and circulatory systems
(white blood cells) are first-line defenses.
Why Do We Get a Fever When
We’re Sick?
• White blood cells (WBC) constantly patrol
your body looking for invaders. If the
WBCs can’t destroy the invaders fast
enough, you might get a fever. Many
pathogens are sensitive to temperature.
A fever slows their growth but speeds up
your body’s defenses.
Antigens and Antibodies
• Molecules that are foreign to your body are
called antigens.
• When your body detects antigens, killer T cells
are formed and they release enzymes that target
antigens. Helper T cells are also released to
stimulate antibody production.
• Antibodies attack specific antigens. Some
antigens have a memory and stay in the blood
to attack antigens should they return later (exchicken pox).
Active Immunity, Passive
Immunity, and Vaccinations
• In active immunity, your body makes it’s own
antibodies to fight off an antigen.
• In passive immunity, antibodies that have been
produced in another animal are injected into
you.
• Vaccinations are used to ward off childhood
diseases (measles, mumps, whooping cough).
Parts of a virus are injected into you and you
develop antibodies specific to certain diseases.
Cases of Disease Before and After Vaccine
Availability in the U.S.
DISEASE
CASES/YEAR PRE-VACCINE
Measles
Diptheria
Mumps
Whooping Cough
503, 282
175, 885
152, 209
147, 271
POST-VACCINE 1998
89
1
606
6,279
Why Get Tetanus Shots?
• Tetanus is caused by bacteria found in soil that
paralyzes muscles. We were given a vaccine
when younger that gave us passive immunity,
but it only lasts 7-10 years. When we get a
puncture wound, we get a booster shot (also
containing diptheria vaccine) that lasts long
enough to keep us from getting the disease.
Usually, the antibodies in the vaccine come from
humans, but sometimes it comes from horses or
cattle.
Infectious Diseases
• Until the advent of the microscope, we had no idea
that diseases could be passed from one person to
another. We also had no clue that these diseases are
caused by living organisms. Louis Pasteur discovered
that microorganisms could spoil milk and wine and
realized that they could attack humans in the same
way.
Disease Organisms
Bacteria (strept throat, pneumonia, plague)
2. Protists (malaria, sleeping sickness)
3. Fungi (athlete’s foot, ringworm)
4. Viruses (colds, flu, AIDS, smallpox)
Smallpox
Mumps
How Diseases Spread
• Infectious diseases are spread by:
a. Direct contact with infected organism.
b. Through water and air.
c. On food.
d. Contact with contaminated objects.
e. Biological vectors (rats, cats, dogs,
birds, mosquitoes, fleas, flies).
Disease Prevention
• Most diseases can be prevented by
cleanliness. In the 1800’s, Joseph Lister
figured out that washing his hands and
surgical instruments before and after
surgery resulted in fewer patient deaths.
• Wash hands.
• Brush and floss teeth.
• Exercise, eat right, get plenty of rest.
Noninfectious Diseases
Diseases that are not spread from one
person to another.
• Chronic Diseases
• Allergies
• Diabetes
• Chemicals and Disease
• Cancer
Chronic Diseases
• Diseases that seem to linger, or last a long
time. Some can be cured, others cannot.
Allergies – overly strong reactions of the
immune system to a foreign substance.
• Things that cause allergic reactions are
call allergens. They can be foods, dust,
pollen, molds, antibiotics.
• When you come in contact your body
forms antibodies and releases histamines.
Diabetes
• A chronic disease associated with levels of
insulin produced by the pancreas.
• Insulin is needed for glucose to pass from
blood into your cells.
• Symptoms: fatigue, excessive thirst,
frequent urination, tingling in hands/feet.
• Can lead to blurred vision, kidney failure,
heart attack, stroke, poor circulation to
feet, coma, death.
Chemicals and Disease
• Toxic chemicals can cause birth defects,
cell mutations, cancers, tissue damage,
chronic disease, and death.
• Asbestos → lung disease
• Lead-based paints → CNS damage
• Alcohol → birth defects
• Pollution → variety of negative affects
Cancer
1)
2)
3)
4)
5)
Characteristics of Cancer Cells
Cell Growth is uncontrolled.
These cells do not function as part of your body.
These cells take up space and interfere with normal bodily
functions.
The cells travel throughout your body.
The cells produce tumors or abnormal growths anywhere in
your body.
Various Tumors
Cancer Treatments
• Surgery.
• Radiation treatments with x-rays.
• Chemotherapy – the use of chemicals to
destroy cancer cells.
While there has been success with the
above treatments, the key is early
detection and treatment.
Early Warning Signs
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Changes in bowel or bladder habits.
A sore that does not heal.
Unusual bleeding or discharge.
Thickening or lump in the breast or elsewhere.
Indigestion or difficulty swallowing.
Obvious change in a wart or mole.
Nagging cough or hoarseness.
The Key to Good Health?
Eat right.
Get plenty of rest.
Minimize stress in your life.
Don’t abuse your body.
See your doctor regularly.
Don’t ignore your body!