Download Where can pathogens enter the body? How the body tries to stop

Where can pathogens enter
the body?
CUTS IN THE SKIN
THROUGH THE NOSE
THROUGH THE EYES
THROUGH FOOD
How the body tries to stop them
from entering.
THESE ARE QUICKLY COVERED BY
CLOTTED BLOOD (SCABS) TO KEEP
INFECTION OUT.
HAIRS IN THE NOSE TRAP DUST AND
MICRO-ORGANSIMS. ANY WHICH ARE NOT
STOPPED BY HAIRS ARE TRAPPED BY STICKY
MUCUS IN THE AIRWAYS WHICH SLOWLY
MOEVES THEM BACK TO UP THE THROAT
WHERE THEY CAN BE SWALLOWED OR SPAT
OUT.
THESE PRODUCE CHEMICALS
IN TEARS WHILL KILL
BACTERIA
ACID IN TE STOMACH KILLS
MOST (BUT NOT ALL)
BACTERIA.
WHO ARE YOU?? (antigens)
Once inside the body, micro-organisms are recognised as being foreign by
our white blood cells. This means that our white blood cells know that they
are not meant to be in the body and so they go about killing them.
A cell from the body
A pathogen.
All the cells of our body are covered in protein markers called antigens.
Every single cell in our body has the same type of antigen. When a
pathogen enters the body the white blood cells notice that it has different
antigens to normal body cells and therefore it does not belong in the body.
The diagram above shows how antigens can be different.
The 3 responses of
white blood cells
Why the response is
successful
Ingesting pathogens
This one is self explanatory. The white blood cells
swallow and digest the pathogens using enzymes.
Producing antibodies
These are chemicals which kill certain bacteria
or viruses
Producing antitoxins
These counteract any toxins produced
by pathogens.
Medicines like painkillers help to treat the _______________ of disease but they do not
kill the pathogens that cause the disease. Some _______________ can be used to kill
bacteria inside our body. Others can be used to stop bacteria from reproducing.
_______________ cannot be killed using antibiotics because viruses reproduce inside
cells. Using drugs to kill viruses might damage the _______________ of our body and
make us ill. If we are _______________ to a pathogen it cannot harm us. We can be
vaccinated to make us immune to some pathogens. A vaccine contains dead pathogens.
So jkscrg
antibiotics
cells
immune
symptoms
viruses
Vaccinations are made of dead or inactive forms of a pathogen. Once injected
inside the body our white blood cells recognise their antigens as being foreign and go
about making the correct antibodies to destroy these cells.
If, in the future we become exposed to a live version of this pathogen our immune
system can respond much more rapidly because our white blood cells “remember” how
to make the correct antibody. This means the pathogen does not have the time to
make us ill – we are immune!
An example of a common vaccine is the MMR which vaccinates children against
mumps, masles and rubella