Transcript Spread of Bacterial Infection

Spread of Bacterial
Infection
Bacteria which cause disease are called
PATHOGENS.
 Once pathogenic bacteria enter body they
produce TOXINS
 Toxins travel through body via blood
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Fighting Bacterial Diseases:
– Sweat on skin kills some bac.
– Tears with enzymes destroy some bac.
– Mucous traps and causes you to cough up
bac.
– Cilia in respiratory tract catch and remove
bac.
– Stomach Acid destroys some bac.
Internal Defenses – Immune Response:
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White blood cells enter infected tissue &
destroy pathogens through phagocytosis
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Undigested pathogens stimulate the
lymph nodes to produce memory cells and
plasma cells
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Plasma cells make antibodies designed to
destroy that specific pathogen.
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Antibodies circulate through the blood
stream to fight any remaining pathogens
•
Memory cells are stored in the lymph
nodes. They contain the instructions of
how to make antibodies for that specific
pathogen if it ever enters body again.
(Fig.4 pg. 122)
Immunity to Bacterial Diseases:
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Active Immunity – the body makes antibodies to
fight a specific disease, can also get this through use
of vaccines.
Vaccine – injection of dead or weakened pathogen to
stimulate the immune response.
Passive Immunity – antibodies are put into the
bloodstream either naturally or by injection of
antibiotics
Natural – pass from mother to fetus during last
month of pregnancy
Antibiotics – any natural product which inhibits the
growth of another living organism, many are fungi, eg:
Antibiotic Resistance:
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Antibiotics first discovered in 1940’s
More than 250 naturally-occurring antibiotics to
treat infections
Over past 60 years bacteria been developing
resistance to antibiotics
When first exposed to antibiotics, weaker strains of
bacteria die
Surviving bacteria may have slight genetic difference
These reproduce and pass on difference (resistance)
*70% of all antibiotics made are fed to livestock,
often added to healthy animals’ feed.
The Eyes of Nye-09-(Antibiotics)