Diseases by MikeJenny


Lack of Homeostasis
1. What is disease?
 A disease is any change, other than
  an injury, that disrupts the normal
  functions of the body.
 The opposite of homeostasis.
   2. Give 5 causes of disease.
1. Genetics –you are born with a the disease, it is
  in your DNA
2. Infection – you catch the disease from another
3. Environment – you can get diseases from
  pollutants and poisons where you live.
4. Organ Malfunction – you can get a disease
  when one or more of your organs is not
  functioning properly.
5. Lifestyle Choices - like…
3. What is a pathogen?

   Disease-causing agents such as bacteria,
    viruses and fungi are called pathogens.
   Pathogen means “sickness maker.”
   Diseases caused by pathogens are
    generally called infectious diseases
    because the agents that cause them
    usually enter, or infect, the body of the
    person who gets sick.
4. What are 5 ways diseases
are spread?
1.   Coughing
2.   Sneezing
3.   Physical contact (STDs)
4.   Contaminated water or food
5.   Infected animals (vectors)
The Immune System
   The body’s
1. What is the immune
   The immune system is the body’s
    primary defense against pathogens.
    It consists of nonspecific and specific
    defenses against infection. It includes
    the skin, blood, lymph nodes, lymph
    vessels and spleen.
2. Define Immunity.
 Immunity is the resistance of an
  organism to disease. If you are
  immune to a disease you will not get
 Will Smith was immune to the disease
  in the movie I Am Legend. He will
  never get the disease.
3. Define Susceptibility.
 Susceptibility is the organism’s lack of
  immunity. If you are susceptible to a
  disease you may get sick when
  exposed to it.
People who do not get a flu vaccine
  shot are susceptible to the flu and will
  get sick if they are exposed to the
4. What is the Human body’s
1st line of defense?
 It is the intact skin and mucous
  membranes, which release
  antibacterial fluids such as mucus,
  saliva and tears. The body’s first line
  of defense against disease is designed
  to keep invaders out!
 Nonspecific meaning it blocks
     5. What is the Human body’s
     2nd line of defense?
   The body’s second line of defense is the
    inflammatory response. It involves sending
    white blood cells (phagocytes) to the site of
    the invasion. They use phagocytosis to engulf
    invading pathogens that have made it past
    the skin into the body. This is what is
    happening when you get inflammation!
   Nonspecific because they will engulf all
   Draw it…
6. What is the Human body’s
3rd line of defense?
 The immune response is the body’s
  third line of defense.
 It is specific, meaning the response is
  different depending on the invader.
a. How does a fever help
fight infection?
   An elevated temperature slows down or
    stops the growth pathogens.
   The higher temperature speeds up the
    heart beat to get white bloods cells
    (phagocytes to the site of infection faster.)
   An increased temperature speeds up the
    activities of the white bloods cells and the
    rate of the chemical reactions that help
    repair damaged tissue.
Viruses living or non

Viruses cannot reproduce
by themselves. They
infect your body cells and
use their machinery to
make more viruses. They
destroy your cells as they
do this, making you feel
sick and doing damage.
b. What are interferons and
how do they fight infection?
 A group of proteins produced by virus
  infected cells that help other cells
  resist the virus.
 They are called interferons because
  they interfere with the virus. They slow
  down the reproduction of the virus
  and give the immune system time to
The Immune Response
     The body’s reaction
    1. Define Antigens and give
    6 examples.
   An antigen is a protein found in the cell
    membrane. Your body recognizes it’s own
    antigens as “self” and antigens on pathogens
    as “invaders.”
   The following have antigens that can trigger
    an immune response.
   Pathogens             Allergens
1. Bacteria           4. Pollen/Dust
2. Virus              5. Foods
3. Fungus             6. Pet Hair
      Body Cell                 Pathogen


Because antigens are made of protein, what is
        going to be very important?
2. Define Antibodies.
 An antibody is a protein produced by
  the body that combines with an
  antigens in the membrane of the
  pathogen and this neutralizes it (so it
  can’t make you sick).
 Masses of pathogens and antibodies
  are then engulfed and destroyed by
  white blood cells.
    3. Describe how ANTIGENS
    and ANTIBODIES fit together.
 Antibody and antigen fit together like
  a lock and key. They are made of
  protein so SHAPE is important.
 Each antibody is specific for a single
  kind of antigen.
4. This antibody is specific for one of the
antigens shown. Circle the correct antigen.

            (Hint shape is important here!)
5. What three areas of the body
make antibodies?
Lymphocytes (white blood cells that
  make antibodies are found in the)

 1. lymph nodes

 2. bone marrow

 3. spleen
6. How do antibodies and phagocytes
work together to fight pathogens?

 Antibodies bind to antigens on
  pathogens (invaders like viruses and
  bacteria) and clump them together in
  large masses.
 These large masses are engulfed and
  destroyed by special white blood cells
  called phagocytes.
7. Draw a phagocyte engulfing the
antigen-antibody complex below:
8. Explain the functions of 3 types of
Lymphocytes “White Blood Cells.”

   1. Memory B Lymphocytes – white
    blood cells that respond to specific
    antigens by beginning to produce
    antibody proteins that will bind only
    with that antigen. As time goes on
    the body will have many different
    types of B cells, each producing
    antibodies for one specific antigen.
8. Explain the functions of 3 types of
Lymphocytes “White Blood Cells”

2. Killer T Lymphocytes – white bloods
  cells that recognize cells in the body
  that have been infected with
  They punch holes into the infected
  cell sometimes injecting poison in to
  kill the microorganism and often the
  infected cell along with it.
8. Explain the functions of 3 types of
Lymphocytes “White Blood Cells”

3. Helper T Lymphocytes – Help B cells
  and Killer T cells do their jobs.
They are the cells that are destroyed by
  the human immunodeficiency virus
  (HIV), which results in the disease
  called AIDS. When these cells cannot
  do their job the immune system is
  weakened significantly.
1. Passive Immunity:
a.   Definition: Antibodies produced by
     another organism are given to an
     individual. The antibodies produce a
     passive immunity against a specific
     pathogen. You do NOT get a memory B

b. How long does it last? As long as they
   remain in the blood stream, usually for
   several weeks until the body destroys the

   Explain Maternal Immunity: The
    mother passes antibodies to the fetus
    through the placenta and to a
    newborn through breast milk. This
    protects the baby from infections
    during the first few months of its life.
2. Active Immunity
a. Definition: The individual builds its
  own antibodies by being exposed to
  the disease in a strong or mild form.
b. How long does it last? For a lifetime
  because you have your own Memory
  B Lymphocytes for that produce
  antibodies against that disease.
1. Vaccination:
You are injected with a weakened form of a
   disease. It doesn’t make you sick it just gives
   you the memory B cells to make antibodies
   against the disease. Polio vaccine
2. Exposure to the pathogen: Your body will
   naturally build up antibodies that last forever.

Have you ever had chicken pox?   If so, when?
Did you get it a second time?
         Problems with the
Autoimmune Diseases
1. Explain what happens to the body.

Autoimmune diseases occur when the
 immune system makes a mistake and
 attacks the body’s own cells doing
Diabetes (Juvenile-Onset):
 An autoimmune reaction that attacks the
  insulin producing cells in the pancreas.

   The person does not produce insulin and
    must have injections of insulin to regulate
    blood sugar. (Can’t maintain
Immune Deficiency Diseases
1. Explain what happens to the body.

 The bodies immune system is under-
 active because it has been
   What is AIDS?
It is an acquired disease, not inherited, that
    weakens the immune system and causes
    certain symptoms. They have a lowered
    number of helper T lymphocytes.
 What is HIV?
Human Immunodeficiency Virus is the virus
    that causes the symptoms that we call
    AIDS. It kills off helper T Cells gradually
    causing AIDS. This can take a while to
    make someone sick.
a. Explain what happens to the body.
Antigens from allergens bind to mast
  cells, immune cells, and causes them
  to release histamines.

b. What are histamines?
Released by mast cells they cause
  runny nose, itchy eyes and skin and
  watery eyes.
 Explain Peanut Allergies
 When people eat peanuts they have
  an allergic reaction because their
  body recognizes the antigens on
  peanut cells as an invader and
  attack. This can cause inflammation
  that causes trouble breathing.
 Do you have an allergy?
   When someone gets a transplant.
    The antigens on the organ must
    match or be very similar to the
    antigens in the sick person’s body.
    Then their immune system will not
    attack it.
 Do not give you immunity.
 They only work with bacterial
  infections NOT viruses.
 They kill bacteria in your body.

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