| Immune System |
Body's
primary defense against disease-causing microorganisms
|
-immune
system comprised of nonspecific and specific defenses -system defends against all foreign microorganisms |
| Nonspecific Defenses |
Defense mechanism
of the body that guards against all infection rather than a particular
pathogen
|
-skin is most important
defense -pathogens cannot penetrate layers of dead cell, acidic conditions kill bacteria -mouth + nose have defenses too |
| Lysozyme |
Enzyme that
breaks down the cell walls of many bacteria
|
-enzymes include mucus, saliva, sweat, and tears |
| Inflammatory Response |
Defense mechanism
that begins when a number of pathogens enter the body, causing fluid and
white blood cells to leak from blood vessels into tissue
|
-allows phagocytes to attack bacteria |
| Phagocyte |
White blood
cell that engulfs and destroys microorganisms
|
-attack bacteria during the inflammatory response |
| Inflamed |
Reddish swollen
area of the skin at the site of infection
|
-literally means "on fire" |
| Lymph Node |
Structure in
the lymphatic system that acts as a filter and produces special white
blood cells
|
-sometime infections
spread through lymphatic system -lymph nodes cause swelling + tenderness as white blood cell fight infection |
| Fever |
Human body's
response to an infection that results in increased body temperature in
an effort to kill pathogens with heat
|
-If pathogens spread
throughout body, body uses fever -produces more white blood cells, stimulates cells to raise temperature -many organisms can only live in small temperature range |
| Interferon |
Protein
that helps other cells resist viral infection
|
-discovered
1957
-virus-infected cell release it to help other cells resist -inhibits viral synthesis and production |
| Specific Defense |
Defense
mechanism directed toward a specific disease-causing agent
|
-used
after pathogen gets past nonspecific defense -triggered by antigen |
| Antigen |
Foreign substance
that induces an immune response and interacts with specific antibodies
|
-carbohydrates,
proteins, lipids on surface of virus, bacteria and other pathogens
|
| Lymphocyte |
A white blood
cell that responds to the presence of antigens
|
-different
kinds used for production of antibodies
|
| B-lymphocyte |
White blood
cell responsible for producing antibodies
|
-matures in
bone marrow
|
| Antibody |
Special protein
that can bind to an antigen on the surface of a pathogen and help destroy
it
|
-shaped like letter Y |
| Antigen-Binding Site |
Area on an antibody
molecule that allows it to bind to an antigen
|
-antibody
has two identical
-by attaching to antigens, antibodies start agglutination |
| Agglutination |
Process in which
viruses are linked together in a large mass by a group of antibodies
|
-agglutinated viruses cannot
enter cells |
| Plasma Cell |
Specialized
B-lymphocyte that releases antibodies into the bloodstream to deal with
an infection
|
-small fraction
of B-cells activated when pathogen invades body
-these grow and divide rapidly to make plasma cells |
| Primary Immune Response |
Production of
antibodies from the first exposure to an antigen
|
-weaker than
secondary immune response
|
| T-lymphocyte |
Lymphocyte that
matures in the thymus gland
|
-assists and
regulates plasma cell production
|
| Immune |
Condition in
which a body is able to permanently fight a disease using B-cells and
T-cells produced the first time the body was exposed to the disease
|
-caused by secondary immune
response |
| Secondary Immune response |
Defense mechanism
that occurs when a pathogen reappears in the body
|
-stonger than
primary response
-produces antibodies so quick disease does not get chance to develop |
| Vaccination |
Injection of
a weakened or mild form of a pathogen used to produce immunity
|
-comes from
Vacca meaning cow
-causes active immunity |
| Active Immunity |
Type of immunity
produced by the body when stimulated by a vaccine or by exposure to a
pathogen
|
-called active
bacause ability to luanch acitve immune response against pathogen
|
| Passive Immunity |
Type of immunity
that results when antibodies produced by other animals against a pathogen
are injected into the bloodstream
|
-only works
as long as antibodies are in bloodstream, usually for several weeks
|
| Killer T-cell |
Special type
of immune cell that transfers proteins into the cell membrane of a pathogen,
causing the pathogen to rupture and die
|
-most effective
attacking cell in immune system
|
| Cell-Mediated Immunity |
Immune response
in which killer T-cells cause the cells of pathogenic organisms to rupture
and die
|
-very important
against eukaryotic pathogens, such as fungi and protozoa
|
| Rejection |
Process in which
the immune system damages and destroys a transplanted organ
|
-caused by
killer T-cells
-T-cells recognize transplanted tissue as foreign and attacks it |
| Allergy |
Reaction
of the immune system that results when antigens bind to mast cells
|
-allergies
produced by pollen, fur, and other antigens -mast cells are found all over body but mostly in nasal passages -bind to mast cells and produce histamines |
| Histamine | Chemical released from mast cells when allergy-causing antigens attach themselves to mast cells; responsible for producing allergy symptoms |
-increase
flow of blood and fluids to surrounding areas
-cause sneezing, runny eyes and nose, and other irritations |
| Asthma | Allergic reaction in which smooth muscles contract around the passages leading to the lungs |
-makes breathing
difficult
-scientists not certain why some people oversensitive to antigens |
| Autoimmune Disease | Condition in which the immune system attacks the body's own cells |
-some infections
trick immune system into attacking self
-ex. streptococcus similar antigen as cardiac cell proteins, anitbodies attack heart |
| Rheumatic Fever | Autoimmune disease that results when antibodies produced to destroy untreated streptococcus bacteria attack cardiac cells as well |
-caused by
fact that streptococcus antigens too similar to cardiac cell proteins
-killer T-cells cause cell death and scaring of heart lining and valves -prevented if antibiotics used promptly |
| Rheumatoid Arthritis | Destructive inflammation of the joints produced by the actions of the immune system |
-usually first
appears between ages 30-40
-exact cause is unknown |
| Juvenile-Onset Diabetes | Diabetes that appears in childhood; may be the result of an autoimmune reaction against the insulin-producing cells of the pancreas |
- causes blood
sugars to be too high
|
| Multiple Sclerosis | Nerve disease that results from autoimmune destruction of myelin sheath that surrounds nerve fibers |
-first symptoms
appear between ages 20-40
-may be caused by viral infection |
| Acquired Immune Deficiency Syndrome (AIDS) | Condition in which certain cells of the immune system are killed by infection with HIV |
-death of
helper T-cells cripples immune system
-never kills people, whatever person catches kills them -patients develop protozoan infection of lungs, fungal infection in mouth -may take 6 months to 10 years to develop -spread: HIV present in blood and body fluids -transmitted through sexual contact, blood transfusions, intravenous drug use, passed from mother to unborn child -nor cure, but can prevent by avoiding exposure to HIV |
| HIV | Human immunodeficiency virus; virus that causes AIDS |
- is a retrovirus
-kills helper T-cells -reproduces and eventuall kills cells -body produces antibodies but virus is in immune system so is not affected -gradually kills off majority of helper T-cell population |
| Helper T-cell | Cell of the immune system that helps other lymphocytes respond to the early stages of an infection |
