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72 terms

Lines of Defense and Viruses Pre IB Biology

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Pathogens
disease-causing organisms
1st line of defense (non-specific)
prevent pathogens from entering cells
skin
the first few layers of cells are dead and cannot be invaded; the living cells are small and tightly connected to each other.
mucus
is a secretion of the epithelial cells that line the respiratory, digestive, urinary, and reproductive tracts. Mucus traps pathogens. In the respiratory tract, cilia on the epithelial cells, sweep the mucus to the throat, where it is swallowed.
HCl
hydrochloric acid in the stomach kills pathogens
lysozyme
enzyme in tears and saliva that can lyse bacterial cell walls
trap or block dust with pathogens
nasal hairs, eyelashes, earwax, etc.
2nd line of defense (non-specific)
mechanisms that reduce pathogen growth or destroy pathogens that enter the cells
inflammatory responses
the release of histamines by mast cells that cause itchiness, fluid leaking from capillaries, and an increase in blood flow to the area
mast cells
a type of white blood cell fixed in tracts and in epithelial tissue
fever
is the body's response to pathogen invasion; elevated temperature can slow bacterial growth and speed activity of white blood cell's
phagocitic cells (such as macrophages)
are fixed in the lungs and lymph vessels that engulf pathogens and foreign materials
interferon
chemical made by body cells infected with viruses to help nearby cells resist invasion by those viruses.
3rd line of defense (specific)
how the immune response occurs.
Macrophage engulfs a pathogen and displays the foreign antigens on its cell membrane receptors.
step 1
Many versions of helper T cells are floating in the blood.
step 2
The correct helper T cell bind to the activated macrophage; the activated helper T cell releases growth chemicals.
step 3
The activated helper T cell bind to the correct B cell.
step 4a
The correct B cells divide to produce plasma cells that will then release antibodies.
step 4b
Some B cells differentiate to long lived memory B cells.
step 4c
Chemicals from helper T cells cause Cytotoxic T cells to divide. These kill infective body cells with chemicals (perforins).
step 5
The antigen-antibody complex, the dead body cell, and the dead WBC's will be engulfed by macrophages.
step 6
Memory B cells and antibodies will remain in the blood to confer immunity.
step 7
antigen
a protein on the surface of a pathogen or a body cell that is recognized by immune system cells.
nucleic acid core; protein; capsid
A virus is made of a _________ (center) and a _______coat called a ______.
viral nucleic acids; viral cells
A virus' nucleic acid codes for making more __________ and ____________.
lytic cycle
the life cycle exhibited by a virus which is causing an infection.
ribosomes
a virus needs to invade a host cell to use the cell's _________ as a site for protein synthesis.
cells
a virus is NOT considered alive because it is not made of _______.
antibodies; our cells don't have cell walls
bacteria are pathogens which can be killed by medications called _________ because most of these medications work by destroying the cell walls of bacteria. These medications do not hurt our cells because ________________________.
measles, mumps, rubella
three examples of virus caused human diseases
staphylococcus, salmonella, cholera
three examples of bacteria caused human diseases
antibodies
Helper T cells, cytotoxic T cells, plasma cells, macrophages and memory B cells are a few types of _________.
antibody
a Y shaped protein specific to an antigen
plasma cells
produce antibodies
helper T cells
become activated when they bind to an activated macrophage
memory B cell
long-lived cells that are specific to an antigen of a pathogen
B cell
a cell type that is stimulated to divide when it recognizes an activated helper T cell
cytotoxic T cells
cell type that kill infected body cells
HCl; defense 1
the chemical in stomach fluid which kills bacteria
lysozyme; defense 1
a chemical in tears and saliva which destroys bacterial cell walls
phagocitic cells; defense 2
large blood cells which circulate in the lungs or in the lymph nodes, and in the fluid between cells that engulf pathogens
immune response; defense 3
the production of antibodies against a specific pathogen
histamines; defense 2
chemicals made by mast cells in response to allergens or pathogens; they cause the inflammatory response
fever; defense 2
the elevation of body temperature
retrovirus
if the nucleic acid of a virus is RNA then the virus is a __________.
RNA to DNA
Before the viral genome can be incorporated into the host cell, it must first convert its ____ to ____. (for retrovirus)
nonliving; cells
Viruses are _______ because they can only reproduce inside living _____.
smaller
Viruses are _____ than bacteria.
lytic cycle
cell immediatly begins producing virus particles upon infection.
lysogenic cycle
the viral DNA is incorporated into the host's DNA and the viral DNA will not be "turned on" until triggered by a later conditions.
thymus gland
T cells mature in the _________.
bone marrow
B cells mature in the _______.
active immunity
when the body produces its own antibodies against an antigen.
natural active immunity
a pathogen enters the body, infection occurs, and the immune response follows
lifelong protection
natural active immunity results in _____.
artificial active immunity
a vaccine stimulates the body to produce antibodies and memory B cells
decades of protection
artificial active immunity results in _____.
passive immunity
antibodies are received from another source (made elsewhere)
natural passive immunity
antibodies passed from mother to unborn child or in the milk
temporary protection for a few weeks
natural passive immunity results in __________.
artificial passive immunity
receiving an injection of antibodies specific to an antigen (such as antivenom)
autoimmune disease
occurs when the body's immune system begins to attack its own cells in a case of mistaken identity.
lupus, rheumatic fever, multiple sclerosis
three examples of autoimmune diseases
Edward Jenner
first made a vaccine against smallpox and introduced the word virus.
Louis Pasteur
discovered the most infectious disease.
pathologist
a person who studies the structural and functional changes cause by disease.
epidemiologist
the scientist who figures out what causes a certain disease and why some people get the disease while others don't. Then they tell people how to prevent it.
Inoculation
the introduction of biological material into a medium.
Incubation
the maintenance of microbiological cultures at specific temperatures for a given time.
culture medium
a substance on or in which microorganisms and other small organisms can be cultured.
Koch's postulate
text that demonstrates the cause and effect relationship between specific bacterium and the disease it caused.