ap biology 2006-2007 immune system wbc attacking cancer cell lymph system
TRANSCRIPT
AP Biology
200
6-20
07
Immune System
WBCattackingcancer cell
lymphsystem
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Vocabulary of Immunity
DiseaseAny condition that disrupts the homeostasis of an organism.
PathogenForeign organisms that cause disease. (microorganisms)
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1. Pathogens2. Toxins in the environment3. Inheritance… Gee thanks, mom!
What causes disease?
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Pathogens of DiseaseVirus Common Cold, Influenza, HIV, Chicken Pox, Measles
Bacteria Strep Throat, Syphilis, E-coli, Food Poising
Fungus Athletes foot, Ringworm
Parasites Leeches, Tapeworms, Malaria, Lyme Disease
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Other Causes of Disease
Cause of Disease
Examples
Inherited Disorders
Down Syndrome, Cystic Fibrosis, Sickle Cell Anemia, Type 1 Diabetes
Exposure to toxins
Exposure to asbestos -> MesotheliomaLead poisoning, radiation poisoning
Poor nutrition Scurvy, Blindness, Lack of Iodine (Goiter)
Organ malfunctions
Hear Attack, Diabetes, Stroke
High risk behaviors
Lung Cancer, Drug Addiction, Skin Cancer, STD’s
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HOW ARE DISEASES SPREAD?
Coughing Sneezing Physical Contact (Saliva, Blood, Bodily
Fluids, Skin Contact) Contaminated Food or Water Infected Animals (Vectors)
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To protect and defend the body against pathogens
The Immune System
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How does the Immune System Work?
2 ways:
1. Nonspecific defenses-
Tries to keep everything OUT! Skin, mucus, cilia, tears, stomach acid, saliva, sweat
2. Specific Defenses-
Fights off infection once the
pathogen gets inside the body. White Blood Cells (WBC’s)
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If the pathogen gets inside anyway, there are things your body usually does to try to slow the invader down…
1. Increased Body Fever: Denatures pathogen’s proteins
2. Expanding blood vessels: (red and warm)
Increased blood flow to area
= More RBC’s & clotting factors for repair
= More WBC’s to fight bacteria (pus)
Inflammation
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Antigen chemical name tags on the surface of every cell = Protein
The body recognizes invaders!
disease-causingbacteria
disease-causingvirus
one of yourown cells
antigens say:“I belong here”
antigens say:“I am an invader”
antigens say:“I am an invader”
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Some kill pathogens
Some produce antibodies
White Blood CellsAKA: leukocytes, lymphocytes, plasma cells, eosinophils, neutrophils, basophils,
monocytes, macrophages
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Patrolling B cells make antibodies against invader immediately
Memory B cells remembers invader can make antibodies
quickly the next time!
B cells
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Antibodies- proteins that either kill invaders or mark them for killing
Antibodies are SHAPE SPECIFIC to pathogens!
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B cells immune response
invader(foreign antigen)
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B cells
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Memory B cells
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Patrolling B cells
Make & release antibodies
recognition
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Antibody “fits” with antigen
Antibodies already in blood
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The antibody tag says “this is an invader” quick…eat him!
Antibodies:
macrophageeating tagged invaders
invading germs tagged with antibodies Y
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B cells releasing antibodies
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T Cells
Helper T Cells: Notifies other WBC’s of invasion! Killer T Cells: Hunts down pathogens & destroys them!
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1. Exposure to harmless
version of a pathogen
“dead”, weakened
Vaccinations
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2. Immune response produces antibodies to
mark and destroy the invading pathogen!
Antibodies = Shape Specific!!
3. Antibody production guarantees a rapid immune response if there is future exposure to the SAME pathogen!
Most successful against viral diseases Ex: flu, chicken pox, HPV, MMR, swine flu, whooping
cough, polio, small pox
Vaccinations
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Immunity
Immunity = the condition your body has when it already knows how to make the antibodies for a specific disease.
If you get sick with an illness and fight it off, you can’t get the same illness again
Pathogen is recognized! Helper T cells signal the immune system to respond!
B cells make antibodies. Killer T cells start killing!
Types of Immunity
Active Immunity Occurs when a organism is: 1. infected with a disease or 2. gets a vaccine
The organism makes it own antibodies specific to antigen
This type of immunity last a life time (stimulates B cells to make antibodies if re-exposed)
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Types of Immunity
Passive Immunity Antibodies made by another organism (not
you!)
Only last a short time (~1 month, your body will eventually destroy the borrowed antibodies)
Ex: Babies will receive antibodies from their mother when they breastfeed.
Ex: Travelers to foreign countries can get antibodies (injected) against tropical diseases.
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Curing You of Disease
Antibiotics = medicine
Ex: Penicillin, Streptomycin, Tetracycline.
Advantage kill bacteria that have successfully invaded you, without harming
your cells
Disadvantages use only after sick only good against bacteria possible development of resistance by bacteria
(if don’t use correctly) – ALWAYS TAKE THE ENTIRE Rx can get sick again by the same pathogen
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Disruption of Homeostasis…
Auto-Immune DiseasesImmune system attacks body cells
lupus antibodies attack many different body cells
rheumatoid arthritis antibodies cause damage to cartilage & bone
diabetes insulin-making cells of pancreas are attacked & destroyed
multiple sclerosis T cells attack myelin sheath of brain & spinal cord nerves fatal
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AllergiesThe response of the immune system to harmless environmental substances. (It thinks they are pathogens!)
Histamines are the chemicals released to cause the inflammatory response
Ex: Pollen can cause a fever, runny nose, and sneezing
Some allergies can trigger a severe reaction, called anaphylactic shock
This can cause choking due to a constricted airway
When things go wrong…
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Allergens
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Organ Transplants
People who are LIVING can donate a Kidney or a PART of THE:Lung, Liver, Intestine, Pancreas
Tissues that can be donated are:Cornea (coating of the eyeball), Middle ear, Skin, Heart valves, Bone, Veins, Cartilage, Tendons, Ligaments
Organs of the body that can transplanted after death:Kidneys, Heart, Liver, Pancreas, Intestines, Lungs, Skin, Bone marrow, Cornea
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Organ Transplants
When a person receives someone else's organ, the organ has foreign antigens on it.
The recipient’s white blood cells will recognize the organ as foreign, think it is a pathogen, and attack it. (Killer T!)
So, the recipient has to take
immunosuppressant drugs
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Organ Transplants
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HIV: Human Immunodeficiency Virus
Infects helper T cells Helper T cells can’t activate rest of immune system
The body doesn’t hear the alarm
AIDS:Acquired ImmunoDeficiency Syndrome
T cell count very low (200 cells/mm3 instead of the normal 500-1000)
infections by other (normal) pathogens can cause death
Disease of the Immune System
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HIV AIDS
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AIDS:fatigue
diarrheanauseavomiting
feverchills
night sweats
Death fromopportunistic
Infections
HIV/AIDSSymptoms
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HIV/AIDS
Over 33.4 million people are infected with
HIV/AIDS worldwide
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Transmission of HIV
Healthy skin is an excellent barrier against HIV and other viruses and bacteria.
HIV cannot enter the body through unbroken skin.
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Transmission of HIV