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Non specific
response…read more

Slide 2

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Most infections are
communicable ­ capable
of spreading from one
person to another.
A living organism that
transmits infection from
one host to another.
Can occur through a break in the skin. INGESTION
This transmission might be via an Many pathogens that cause gut
injury from contaminated medical diseases are transmitted by
instruments or shared needles, e.g. contaminated food or drink. The risk
hepatitis B. of infection is greatest from raw
How food, e.g. diarrhoea.
DIRECT CONTACT transmitted Many droplets are from your
Important in the spread of respiratory tract. These droplets are
disease in small children. Many full of pathogens if you have an
sexual diseases are spread by infection. When the pathogens are
direct contact of the genital inhaled by another person the
organs, e.g. impetigo. pathogens enter their respiratory
tract and a new infection is set up, e.
g. influenza.
Inanimate objects that carry
pathogens from one host to
another, e.g. hospital towels.…read more

Slide 3

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Antigens can also be toxins
made by bacteria, or
sometimes are whole
microorganisms such as
bacteria or viruses.
Substances which stimulate the production of
an antibody.
They are chemicals on the surface of the cell,
e.g. bacteria, glycoproteins carbohydrates.…read more

Slide 4

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This occurs when the
infection is generally
Mast cells along with white blood cells release histamines.
Histamines cause the blood vessels to dilate, causing local heat and
redness. This:-
·reduces the effectiveness of pathogen reproduction in that area.
·Makes the walls of the capillaries leaky.
Fluid (plasma, white blood cells and antibodies) is forced out of the
capillaries, causing oedema and pain.
The white blood cells and antibodies disable and destroy the
pathogens.…read more

Slide 5

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In bacterial infections the temperature
rises steadily and remains fairly high. In
viral infections, the temperature tends to
spike before dropping to normal again.
When a pathogen infects the body it causes
the hypothalamus to reset to a higher body
Reduces the ability of pathogens to reproduce
so less damage is caused.
Enables the specific response system to work
more effectively at combating infection.…read more

Slide 6

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Phagocytes can be seen
as a pus, which oozes out
of the wound, or it may be
reabsorbed by the body.
They accumulate at the site of infection to
attack the invading pathogens.
Macrophage Neutrophil
·Agranulocyte ­ no granules ·Granulocyte ­ granules
·Make up about 4% of white blood cells ·Make up about 70% of white blood cells…read more

Slide 7

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