Download Topic: Disease: How does our body come under attack?

Topic: Disease: How does our body come
under attack?
1. What is a disease?
Disease is any condition that
prevents the body from working as it
should. As a result the body may fail
to maintain homeostasis.
2. What can cause disease?
Disease in
humans may
result from
foreign invader
organisms
called…..
PATHOGENS
3. Pathogens •Bacteria
•Viruses
•Fungi
•Parasites
Bacteria Characteristics
• Called Prokaryotes
• One-celled organisms
• Lack most ORGANELLES, no true nucleus.
Examples
• Strep throat
• Salmonella – toxins
• Syphilis
• What will the doctor
Give you?
Antibiotics
The salmonella bacteria give off
a toxin that causes you to get
sick.
Bacteria and antibiotics
Virus
• A VIRUS IS NOT A CELL (IT IS NOT ALIVE)
• DNA or RNA + Protein Coat
• Very small, smaller then a CELL.
• They can only reproduce INSIDE a cell.
• A virus works by injecting its DNA into a cell, turning the
cell into a virus producing factory.
Examples
•
HIV
• Chicken Pox
• Influenza
• Can you take antibiotics?
Fungus
•
Athlete’s foot
• Ring worm
• What can the doctor
Prescribe?
• Fungicides
Parasites
Some animals and one-celled
organisms survive by living
and feeding on other
organisms.
4. How are pathogens transmitted?
Blood
Food
Sex
Air
Animal
5. Diagnosing – determine the disease
you have
Diagnosis is made based on symptoms
and an examination
6. Prevention vs. Treatment
Prevention – ways to avoid getting the disease. (wash hands, exercise, diet plans etc.)
Treatment – ways to help people with a disease to get better. (medicine, surgery, diet plans, etc.)
7 Besides pathogens, what else can
cause disease?
Toxic Substances
Poor Nutrition
Organ Malfunction
Inherited
Disorder
Risky Personal
Behavior
Topic Immune System: Structures and Functions: How
does our body defend us from pathogens?
1. Pathogens
Any disease-producing
agent especially a virus,
bacterium, fungus, or
parasite.
2. 1st Line of Defense
• Skin
• Mucus
• Tears in eyes
• Acid in stomach
There are often enzymes in these
substances that are able to destroy
pathogens (tears & sweat). Others like the
stomach provide acidic environments that
are inhospitable to most pathogens. Hair
and mucus serve to trap potential disease
causing pathogens.
3. 2nd Line of Defense
The Immune
System
Cellular Components:
4. White Blood cells
• Large cells with a nucleus.
• Less numerous than RBC’s.
• Defenders of the body.
• Types:
• Phagocytes: engulf and destroy bacteria
(Macrophages)
• Lymphocytes: produce antibodies
(B-Cells)
5. Immune System
Made of proteins, cells, and
tissues that identify and defend
the body against foreign
chemicals and organisms
6. How does our immune system identify foreign
cells?
Antigen
Recognition proteins on our
cells (self) are not targeted
by our immune system.
• A protein on the cell
• The ID tag identifies the
invader as not belonging
to the body (non-self).
• This ID tag is called an
antigen.
• All cells have recognition
proteins!!
7. Phagocytes – Engulf the Pathogens
Phagocytes:
White blood
Cells that
Eat a pathogen
8. Lymphocytes – Produce antibodies
• They can make antibodies,
which are their weapons
against the foreign antigens.
• Antibodies & Antigens are
both proteins!!
9. Antibodies
Pathogen
Antibodies
Antigens
• They are “Y” shaped
proteins, made by
__________
B-Cells
• They are weapons that
fight against pathogens
How are nuts and screws similar to
antigens and antibodies?
Antibodies are made specifically to
match the shape of the antigen.
1 antigen = 1 antibody
What does this remind you of?
11. How do antibodies destroy pathogens?
• When the antibody
attaches to the antigen, it
breaks open its cell
membrane
• Or, the antibody attaches
to the antigen, and a
phagocyte will know to
engulf it
12. Our Immune System has a good
memory!
The first response is
relatively slow and
weak because time
is needed for enough
WBCs to form and
defeat the pathogen.
The second response
to the same pathogen
triggers a quicker and
stronger response.
** After the first response, the immune system “remembers”
specific pathogens by leaving behind WBCs that protect the
body for years (memory cells).
Topic: Vaccines: How does your body become
immune (resistant) to disease?
Bioterrorism
Today there is mounting concern
about the threat
of a bioterrorist
Fatal hemorrhagic
smallpox in a twelve-year-old girl,
1970s, Bangladesh. A genetically - engineered strain of
smallpox might produce
symptoms such as
attack using smallpox
-- sounusual
much
these. Here, the eyes are filled with blood, and blood
form in the mouth
and inside
the body. How can
concern that inblisters
October
2001
the
we protect ourselves?
American government decided to
order enough vaccines to protect
every U.S. citizen.
Smallpox has a fearsome reputation, having
killed more people in history than any other
infectious disease.
1. What is a vaccine?
Antigen
Weakened
Pathogen
Antibody
A vaccine is a dose of a pathogen or part of a pathogen
that has been disabled or destroyed so it is no longer
harmful, but it still has the antigens present.
These antigens trigger an immune response.
How was the first Vaccine developed?
English physician Edward Jenner developed
an inoculation against smallpox in 1796.
Armed with the knowledge that milkmaids
who had been exposed to cowpox, a
relatively mild affliction, didn't come down
with smallpox, Jenner intentionally infected
an eight-year-old boy with cowpox. Two
months later he infected the boy again, this
time with smallpox. As Jenner expected, the
child didn't come down with the disease -- he
was immune.
Vaccines depend on the “memory” of the
immune system.
The first response is
relatively slow and
weak because time
is needed for enough
WBCs to form and
defeat the pathogen.
The second response
to the same pathogen
triggers a quicker and
stronger response.
** After the first response, the immune system “remembers”
specific pathogens by leaving behind WBCs that protect the
body for years (memory cells).
2. How do scientists make vaccines?
•
http://www.pbs.org/wgbh/nova/bioterror/va
ccines.html
1) Obtain pathogen
2) Treat pathogen to kill
or weaken it.
3) Inject altered
pathogen (vaccine)
into organism.
4) Body responds to
antigens by making 5) Some WBCs specific for
this pathogen remain in the
antibodies & having body to protect the organism
WBCs attack invader. from future attacks.
3. What happens when you get
invaded by the real pathogen?
Some
white blood cells
specific for this pathogen
(called Memory Cells) are
already present and will
multiply quickly and
destroy the invader before
it has the chance to cause
the disease.
Memory
Cells
4. What is immunity?
• The ability of a person who once had a disease to be
protected from getting the same disease again.
She was very ugly!
The ugliest one in our
community.
She went to the beauty
parlor so often
She built up an immunity.
5. Immune response
Antibody Concentration
Real Pathogen
Vaccine
Interval
between
exposures
First
exposure
Second
exposure
Time
6. Active vs. Passive immunity
• Active Immunity
• You make your own antibodies
to fight the pathogen
• Long lasting
• Passive Immunity
• You get antibodies from
a different organism, you
don’t make your own
antibodies
• Short lasting
How are these two types of immunity
different?
Topic: How does HIV affect the
immune system?
What could have made him look so
sick?
1. How can we contract HIV?
•
•
•
•
•
Sexual intercourse
Blood transfusion
Passed through the placenta
Open wound
Sharing needles - drugs
2. What is HIV?
• It is a virus that attacks
our immune system.
• It is a retrovirus. It has
RNA not DNA as its
genetic material.
• How does our body
know this is an enemy?
ANTIGEN
3. What part of our immune system does it attack?
White blood cells
HIV attacks special WBC’s called T-Cells
4. How are B-cells different than
T-cells?
Make
antibodies
Send signals
to B-cells
to make
antibodies
HIV
Virus
5. How does HIV replicate?
T-Cell
• HIV binds to a T-cell
• It inserts its RNA into
the T-cell
• It produces HIV DNA
• It hides HIV DNA inside
the cell's DNA:
• This turns the cell into
a HIV factory.
6. Effects
• You don’t die from the HIV infection,
rather you die from the diseases/infections
you get because your body can’t defend
itself. (ex: pneumonia)
• These infections are called
OPPORTUNISTIC INFECTIONS.
Can we make a vaccine?
It is very difficult because the virus mutates very quickly
and produces different antigens after only a few
generations.
Where is AIDS an epidemic?
Topic: How can the immune
system malfunction?
1. How can your immune system
malfunction?
1.
2.
3.
4.
Allergies
Asthma
Autoimmune Disease
Organ Transplants
2. What is an allergy?
• An allergy is a rapid
immune system reaction
to environmental
substances that are
normally harmless.
• Can you think of
materials that can cause
allergic reactions?
3. What are things that cause allergies?
Allergens
BEE POLLEN
RAGWEED
HOUSE DUST
MOLD
4. Allergic reactions
• Inflammatory response:
allergen attaches to mast
cells which release
histamines.
• Histamines are chemical
that call trigger an
inflammatory response
(capillaries swell)
• Hives, nausea, or shock
• What can we take for
allergies?
5. Asthma is an allergic reaction
• Allergic reaction that
causes your respiratory
ducts to swell up
6. Autoimmune disease
The immune System
fails in distinguishing
between self and
non-self.
The word "auto" is the Greek word for self. If a person has an
autoimmune disease, the immune system mistakenly attacks self,
targeting the cells, tissues, and organs of a person's own body.
7. Examples of Autoimmune diseases
Diabetes is a disease, which
prevents the body from properly
using food energy.
In MS, the immune system
attacks the protective
coating around nerves, called
myelin.
Rheumatoid arthritis
Joints swell
8. Why are organ transplants difficult?
• This is a kidney being
removed from a
donor
• The donor will have
his own ID tags on
the cell membrane.
What are these ID
tags called?
9. How will the recipient react?
• A transplanted organ is recognized as
foreign and is attacked by the immune
system (REJECTION).
• The chance of REJECTION is less when the
donor and recipient are closely related or
when anti-rejection medication is used.
10. Why take an immunosuppressant?
It will suppress your immune
system and reduce the chance
of destroying the transplanted
organ.
What is the risk of suppressing
the immune system?
It increases the patient’s risk for
an infection.