| A Giant Network That
Surrounds Our Bodies
Have
you ever asked yourself these questions?
Should
I breathe now?
Is
the amount of the blood that my heart pumps sufficient?
Which
of my cells and organs require how much energy?
When
should my stomach start digesting the food I've eaten?
Is
the intensity of the light entering my eye in due proportion?
Which
muscles should I contract in order to move my arm?
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These
questions sound odd, don't they? That is because we
never ask ourselves such questions. What's more, most
of us are not even aware of the continuous performance
of these processes. Our bodies perform all these processes
automatically. And it uses the network of nerves to
do this. This network is formed by the union of trillions
of nerve cells, which you can see in these pages. We
may compare this network of nerves, which reaches every
corner of our body, to a motorway, as seen in the picture.
Thanks to this network, the cells in our brain are linked
to the muscle cells in our feet, and all body cells
communicate with each other. Yet, our nervous system
has a much more comprehensive system than kilometres
of motorways, which have many crossroads and separate
carriageways for vehicles travelling in opposite directions.
Just as vehicles move from one place to another on motorways,
electrical nerve impulses are transmitted along the
network of nerves in our body. These impulses convey
messages from one region to another.
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These impulses move in your body much
faster than you can imagine. An electrical stimulus
sets out from your brain, for instance, when you want
to flex your arm. During this complicated journey, the
stimulus first stops by the spinal cord. Thence it proceeds
towards the organ concerned, to which the message should
be conveyed. Your arm muscle contracts as a whole and
you bend your arm at the elbow. This
series of actions takes place in a mere thousandth of
a second. Considering that it takes approximately a
second to slowly close and reopen your eyes, one can
better understand how short a thousandth of a second
is. Similarly, stimuli are sent from the entire body
to the brain via the nerves. From every single part
of your body messages are sent to your brain continuously
and at an amazing speed. So you can talk, laugh, run,
taste the flavour of ice cream, play with your dog...
all these processes occur without interruption; you
perform the act immediately as you think about. You
see the object right at the moment you look at it, you
hear the words right at the moment they are uttered,
and perceive whether an object is hot or cold right
at the moment you touch it. All these are thanks to
the perfect harmony between your brain and nervous system.
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Through the nerves all around your body, your
brain constantly receives stimuli from the rest
of your body. The brain evaluates these stimuli
and responds to the relevant parts of your body.
It is these answers provided by the brain that
enable you to move, see and hear. |
Indeed, nerve impulses are active in your
body at this exact moment too. Nerves in your fingertips
send messages to your brain when you read a book, regarding its weight, so that
you lift the book with a force suited to its weight.
In the meantime, stimuli are sent from your eyes, nose,
ears, feet and many other parts of your body to your
brain as well.
Your brain evaluates these incoming stimuli
and sends relevant responses to the concerned parts
of your body, which act according to these responses.
Now let's recall all of these actions. Many processes
occur within your body simultaneously. You read a book
while at the same time you hear sounds from the external
world, feel the soft fur of your cat as it passes between
your legs, taste the flavour of the fruit juice you
drink, your heart keeps beating and many other actions
take place in your body.
What would happen if you were to control
all of these for a few seconds? Surely you would not
be able to control all at the same time. However, thanks
to the perfect creation of Allah, your brain and other
parts of your body operate jointly and execute all these
tasks without needing any intervention of yours. All
kinds of information are transmitted from the body to
the brain in the form of stimuli, which need to be interpreted.
Only then can you perceive the softness of your dog's
fur, the coolness of the wind, the flavour of the peach
juice, the smell of the fried potatoes. Well then, do
you think it is possible for your brain, which is a
piece of flesh weighing not more than 1.5 kilos, to
fulfil all these by itself? Of course not. Thanks to
the splendid creation of Allah, your brain can carry
out all these processes at the same time.
You
would blink your eyes if a friend of yours approached
you silently and clapped his hands suddenly when you
had not noticed his or her coming. There is not another
option, because this is a reflex. A reflex is an immediate
involuntary response. The reason why it is immediate
is that stimuli are not transmitted to the brain in
such cases and the required response is received directly
from the spinal cord. This is a significant gift that
Allah created for us because, thanks to such reflexes,
we are protected from many dangers. For instance, you
can remove your hand immediately when you touch a hot
glass. The reflex is a security mechanism that Allah
created for the protection of our bodies. With the inspiration
of Allah, nerve stimuli proceed in your body at a speed
of approximately 9 kilometres (6 miles) in a second
and so you are protected against many dangers.
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