Defence mechanisms agaist pathogenic diseases.
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Transcript Defence mechanisms agaist pathogenic diseases.
Defence mechanisms against
pathogenic diseases.
And other stuff.
Pathogens
Pathogens are bacteria and viruses that
cause disease.
Infection is a daily event. Sickness
however is not because not all infections
cause disease.
The human body is constantly exposed to
pathogens from the very moment of birth.
You probably contact many potential
pathogens every day.
The immune system is our
primary defense against
microorganisms that cause
disease, and consists of NonSpecific and Specific Defenses
against infections.
Non-Specific Defenses.
Non-Specific Defenses guard against
pathogens in general. Harmful or not.
These defenses are the first line of
protection (after the skin) against
pathogens in the body.
White Blood cells are a non-specific
defense.
Specific Defenses.
Specific defenses are put into action when
the Non-Specific Defenses fail.
These Defenses are attempts by the body
to fend of particular pathogens, usually
harmful ones.
They are the second line of defense. Well
duh!
Circulatory System.
White Blood cells (lymphocytes) in the
circulatory System help the body fight off
pathogens, when an infection occurs your
body makes more white blood cells to fight
the infection.
There are two types of lymphocytes, B
and T. B produces anti-bodies while T
attacks pathogens directly.
The Lymphatic System.
The lymphatic system is the taxi of the immune
system, it carries the white blood cells around to
all parts of the body.
Lymph is the fluid that flows through the
lymphatic system. It carries the white blood cells.
Lymph nodes are situated along the lymphatic
system and their job is to produce phagocytes
which engulf bacteria and poisonous
substances.
Different ways of acquiring Immunity.
Active: When the body is
actively producing its own antibodies due to vaccination or
infection. The body will
continue to make the antibodies after the infection is
gone.
Passive: When the body
receives anti-bodies from the
mothers placenta or when
injected, the anti-bodies
gradually disappear.
New Zealands Immunisation program.
The NZ immunisation program is free for
everyone.
Most of the immunisations are just dead or
weakened cultures of the disease.
Sometimes this isn’t enough for some diseases
so actual anti-bodies for the disease are injected
into the body. (passive immunity)
The injected anti-bodies don’t last very long and
are gradually broken down and destroyed.
Tetanus.
Tetanus is a bacteria which enters the
body through a wound.
Symptoms are Contraction of muscles
(which hurts), especially the jaw and neck
muscles.
Tetanus injections hurt. Lots.
Treating Tetanus.
Sometimes Tetanus develops too quickly and
the body fails to create enough anti-bodies,
sooooooooooo, anti-bodies are injected into the
body instead (passive immunity).
But other times the body creates its own antibodies to fight the disease.
The dead and infected tissue must be removed.
Antibiotics are part of the treatment.
A sick orange!!!
Your lovely
presenters:
Michelle, Anna, Sarah and Soraya.
Incase you missed that it was,
Michle, Ana,
Saraoh and Sorya.
That’s Michelle, Anna, Sarah and
Soraya.