Immunity
Homeostasis in an organism is constantly threatened. Failure to respond
effectively can result in disease or death.
Viruses, bacteria, fungi, and other parasites may infect plants and animals and
interfere with normal life functions(pathogens).
Immune response: defensive reaction of the body to foreign substances or
organisms
The immune system also protects against some cancer cells which may arise in
the body.
Natural Killer Cells destroy the bodies own infected cells, especially those containing
viruses. They may attack cells that might form tumors. AKA.. Cytotoxic T-cells
Antigens: foreign substances or organisms(pathogens) which stimulate the body
to make antibodies
Antibodies: specific plasma proteins which render harmless or destroy a specific
antigen produced by certain white blood cells (ex. lymphocytes) Released by
plasma cells(offspring of B-Cells)
An antibody has a specific shape which only
allows it to attack a specific antigen.
Other white blood cells mark antigens for attack
by antibodies or attack and engulf the antigen.
(phagocytes= macrophage)
Immunity: the accumulation of specific
antibodies in the plasma of the blood enabling
the individual to resist specific diseases.
Ways of acquiring immunity:
1. Active immunity: the individual either
possesses or forms his or her own antibodies
within his or her own body
** The antigen-antibody reaction occurs within
the body in response to either contact with the
disease-causing organisms or their products,
or by receiving a vaccination.
Vaccinations use weakened microbes or parts
of microbes to stimulate the immune system
to react. (primary immune response) This
reaction stimulates the body to fight
subsequent invasions by the same microbes
(memory cells[(offspring of b-cells that do not
turn into plasma cells). (secondary immune
response]
2. Passive immunity: a temporary form of
immunity produced by the introduction of
antibodies into an individual from another
organism "Let the others do the work" This
immunity is of short duration.
allergy--an extreme body reaction to certain
foreign proteins (antigen-antibody rx.)
Some allergic reactions are caused by the
body's immune responses to usually harmless
environmental substances.
autoimmune diseases: the immune system
attacks some of the body's own cells
exs. Crohn's disease, myasthenia gravis,
multiple sclerosis, lupus, fibromyalgia
Antibodies formed in response to these
substances may cause inflammations and/or
result in the release of a chemical substance
called histamine. The histamine causes the
allergic response.
Antihistamine: stops this allergic reaction
AIDS (Acquired immune deficiency syndrome)
 a viral disease which damages the immune
system
 this damage leaves the body unable to cope
with numerous infectious agents and
cancerous cells
Our increased knowledge of immunity has
resulted in the ability to type blood and
transplant organs.
Major lymph vessels have lymph nodes which
contain phagocytic white blood cells which filter
bacteria and dead cells from the lymph.
[Some other causes of disease include]
1.
inheritance
2.
toxic substances
3.
poor nutrition
4.
organ malfunction
5.
poor personal behaviors and choices
Cancer: results from gene mutations in cells
which cause uncontrolled cell division
 Exposure of cells to certain chemicals and
radiation increases mutations and thus
increases the chances of cancer.
Biological research (such as the human genome
project) generates knowledge used to design
ways of diagnosing, preventing, treating,
controlling, and curing diseases of plants and
animals.