Besieged Castle: The Human Body
is a fact that even though we try to live in clean environments, we share
these places with many micro-organisms. If you had the chance to view the
room you are currently sitting in with a microscope, you would immediately
see the millions of organisms you live with.
In this situation, the individual resembles a "besieged
castle". Needless to say, such a castle, which is surrounded by countless
enemies, must be protected in a very complete and organized manner. Human
beings are created along with this perfect protection they need, and are
not, therefore, entirely defenceless against these enemies. The "micro"
guards in our bodies never leave us alone and fight for us on many fronts.
The invader cells that want to take control of
the body first have to fight their way through the front line of the body.
Even though these fronts have their weaknesses at times, the enemy is
hardly ever allowed to pass through them. The first front the enemy must
penetrate is our skin.
The Protective Armour of Our Body: The Skin
The skin, which covers the entire body of a human
being just like a sheath, is full of amazing features. Its ability to
repair and renew itself, its non-permeability by water, despite the existence
of tiny pores on its surface as opposed to its function of discharging
water through perspiration, its extremely flexible structure, allowing
free movement, as opposed to its being thick enough to avoid easy rupture,
its ability to protect the body from the heat, the cold, and harmful sunrays
are only a few of the features of the skin that have been specially created
for human beings. Here, we will deal with a particular feature of this
extraordinary wrapping paper: its ability to protect the body from disease-causing
micro-organisms. If the body is considered a castle besieged by enemies,
we can safely refer to the skin as the strong walls of this castle.
The main protective function of the skin is realized
via the dead cell layers constituting the outer section of the skin. Each
new cell produced by cell division moves from the inner section of the
skin towards the surface. While doing this, the liquid element (cytoplasm)
of the cell interior transforms into a resistant protein known as keratin.
During the process, the cell dies. The newly formed keratin substance
has a very hard structure and is not therefore subject to decomposition
by digestive enzymes, which is a sign of its resistance. Thus, invaders
such as bacteria and fungi will be unable to find anything to rip off
from the outer layer of the skin.
Moreover, dead outer cells containing keratin are
constantly shed from the skin surface. The new cells that come from beneath
to replace the discarded ones form an impenetrable barrier in that area.
The organisms on the skin fulfill another protective
function of the skin. A group of harmless microbes live on the skin, which
have adapted to its acidic medium. Feeding on the leftovers stuck on the
keratin of the skin, these microbes attack all kinds of foreign bodies
to protect their feeding site. The skin, as the host of these microbes,
is like a supplementary force that provides external support to the army
within the human body.
first defense response of the organism against its dangerous invaders
is the rapid self-repairing of the skin tissue following the infliction
of a wound. When such a wound ruptures the skin, defence cells immediately
travel to the injured area to fight with the foreign cell and to
remove the debris of the affected tissue. Later, some other defence
cells enhance the production of fibrin, which is a protein that
rapidly re-covers the wound with a fibrous network. This picture
is of a fibrin that has spread over some red blood cells.
AN IN-DEPTH VIEW OF THE SKIN
Above is a cross-section of the skin. The
sweat droplets secreted from the skin play a variety of roles in
the body. In addition bringing down the body temperature, they provide
nutrition for certain bacteria and fungi living on the surface of
the skin, and produce acidic waste materials such as lactic acid
which helps decrease the PH level of theskin. This acidic medium
on the skin surface creates a hostile environment for any harmful
bacteria that are looking for a place to live.
is a close-up of the sweat gland entrance. Here, too, you will
find bacteria just like everywhere else on the skin.
picture, which is magnified 5900 times, shows the cells in the
trachea (blue). They use their glands (yellow) to secrete a
substance that traps the particles in the air.
you can see the macrophages located in the lung tissues. They
eliminate the dust particles in the air we inhale.xxxxxxxxxx
Protection in Respiration
One of the courses our enemies take to enter our
body is the respiratory tract. Hundreds of varied microbes, which are
present in the air we inhale, try to gain entry to the body through these
passages. However, they are unaware of the barrier set up against them
in the nose.
special secretion in the nasal mucous retains and sweeps out about 80-90%
of the micro-organisms that gain entry to the respiratory system directly
or through dust particles or other substances.
In addition, the tiny hairlike structures (cilia)
on the surface of the cells of the respiratory tract beat upward, causing
a current that carries foreign particles to the throat where they are
swallowed and disposed of by acid in the stomach. The coughing reflex
and sneezing facilitate this function.
The microbes that are able to surmount these barriers
and reach the alveoli (lung, bronchus and gingiva) will be ingested by
phagocytes. After this phase, phagocytes become mobile and drift upwards
with the microbes they have ingested to be finally discharged from the
body in different ways.
Each time you breathe, as you are doing now, a
war is fought at the border gates of your body of which you are completely
unaware. The guards at these border gates fight with the enemy to the
death to protect your health.
Protection in the Digestive System
Another vehicle by which microbes gain entry to our
body is our food. However, the guards of our body, which are aware of this
method used by the microbes, await them in the region where the food finally
ends up, which is the stomach. They also have a surprise for the arriving
microbes, which is the gastric acid. This acid is quite an unpleasant surprise
for the microbes which have overcome all obstacles and reached the stomach.
The majority, if not all, of the microbes are defeated by this acid.
Some microbes may overcome this obstacle because
they have not made enough contact with the gastric acid, or they have
showed resistance. However, these microbes are again subjected to further
conflicts with other guards situated on their way. Now, another surprise
is at hand for them: the digestive enzymes produced in the small intestine.
This time, they cannot get away as easily.
As we have seen, the human body has specially created
guards, which protect the human body in every phase of the microbes' assaults.
There are now some important questions raised by
Who established that microbes living outside would
try to penetrate our body through foods, which route the food would follow,
how microbes would be destroyed in their final destination, where they
would go if they overcame this obstacle, and how in that case they should
be exposed to stronger measures? Is it the body cells, which have never
been out of the body, and therefore, have no chance of examining the chemical
make-up of the microbes outside, and which, moreover, have not received
any training in chemistry?
Definitely not. Only Allah, Who created both the
external world, and the food in this world, and the body that needs these
foods, and the system to digest these foods, is able to create such a
Another Method: Destroying the Enemy by Another
There are many other micro-organisms that live within
the human body which cause us no harm. What are these organisms that continue
with their own life without doing us any harm, and what is their purpose
in living within our body?
These groups of micro-organisms, which are gathered
in certain parts of the body, are called the normal microbial flora of
the body. They do no damage and even have some benefits for the human
These micro-organisms provide external support
for the defence army against microbes. They benefit the body by preventing
foreign microbes from settling in it, because the entry of any microbe
into the body is a threat to their own housing site. Since they do not
want to be displaced by the invaders, they fight a fierce battle against
them. We can think of these micro-organisms as "professional soldiers"
fighting for the body. They try to protect the site they live in for their
own benefit. In so doing, they complement the fully equipped army in our
How do these "professional soldiers" settle in
The human embryo has met no enemy during the gestation
period in the mother's womb. Following the birth of the child, it makes
contact with the environment, and numerous microbes are introduced to
the child through the intake of food and by way of the respiratory tract.
Some of these microbes die right away, while others are discharged before
having the chance to settle down in the body. Some, however, settle in
various parts of the body such as the skin, skin ridges, mouth, nose,
eyes, upper respiratory tract, digestive tract, and genital organs. These
microbes form permanent colonies at these locations and constitute the
microbial flora of the human body.
Who are Our Micro Enemies?
Our micro enemies, on the other hand, are micro-organisms,
which are not a part of our bodies, yet which have somehow penetrated our
bodies, eventually stimulating the defence army therein.
foreign cell that enters the body is not, however treated as an enemy. Foreign
matter constantly enters our bodies as we eat, drink water, or take medicine.
Yet our body does not initiate a war with it. In order for the defence cells
to perceive a foreign substance as an enemy, certain conditions are taken
into consideration such as the size of the molecule, its rate of elimination
from the body, and its way of entering the body.
Among our innumerable micro enemies, bacteria have
an established reputation.
Bacteria, which enter the human body in multiple
ways, instigate a fierce war in the body. Sometimes ending up with quite
serious illnesses, these wars explicitly reveal the power and ability
hidden in an organism the size of a few microns (a micron is one thousandth
of a millimeter). Recent research has shown that bacteria have an extraordinary
resistance even to the most severe and harsh conditions. Particularly,
the bacteria known as spores are resistant to extremely high temperatures
and drought for extended periods. This is why it is difficult to destroy
human body resembles a very valuable diamond stored in a safe, receiving
the most intensive care and protection. Some of the organisms that try to
invade the body act like experienced thieves. One of the best known and
most important of these thieves is the virus.
This organism, whose existence
we became aware of with the invention of the electron microscope, is too
simple-structured and small to be considered even as a cell. Viruses,
which vary in sizes ranging from 0.1 to 0.280 microns, are excluded from
the world of living things for this reason.2
Although categorized as being apart from the world
of living beings, viruses indisputably possess at least as exceptional
abilities as all other living beings do. A closer examination of the lives
of viruses will make this fact more apparent. Viruses are the compulsory
parasites of living beings. This means, they cannot survive if they do
not settle into a plant, animal, or human cell, and consume its food and
energy. Viruses do not have a system that would enable them to survive
on their own. As if they are aware of this, they deftly slip into a cell,
and after invading the cell, with the same deftness turn the cell into
a "virus production factory" that produces its own copies.
This plan developed by the virus to invade the
cell is extremely sophisticated and intelligent. In the first place, the
virus must determine whether the cell is appropriate for itself or not.
It has to be very careful and meticulous in this decision, for the smallest
mistake may cause its death. To avoid such an end, it uses its special
receptors to check whether the cell is appropriate for it or not. The
next important thing it does is to carefully locate itself within the
The virus confuses the cell with the tactics it employs and avoids observation.
is how the events develop: the cell transports the new DNA of the virus
into its nucleus. Thinking that it produces protein, the cell starts to
replicate this new DNA. The DNA of the virus hides itself so furtively
that the cell involuntarily becomes the production factory of its own
enemy and produces the very viruses that will eventually destroy it. It
is indeed very difficult for the cell to identify the hereditary make-up
of the virus as that of an invader.
The virus locates itself within the cell so well
that it almost becomes a part of it. After the multiplication process
is over, the virus and other new viruses depart from the cell to repeat
the same process in other cells. During the process, depending on the
type of the virus and the cell, the virus can kill the host cell, cause
harm to it, modify it, or simply do nothing.
The question of how the cell, which operates under
a very strictly monitored control mechanism, can be deceived into becoming
a virus factory is still unanswered. It is quite intriguing that viruses,
which have a highly specialized structure, but which are not even classified
as living beings, could act so intelligently, think up, and plan such
effective strategies. The secret of this phenomenon lies in the existence
of a Creator, Who created these organisms with the abilities they possess.
The features of the virus are perfectly designed
to enable it to make use of the system operating in the cell. It is obvious
that the power that created the virus is also well informed about the
extremely complex working principles of the cell. This power belongs to
Allah, Who created the virus and the cell into which it will settle, as
He created the entire universe.
The virus, which, with its miniscule structure,
can inflict and sometimes even cause the death of the human body, which
is millions of times bigger than itself in size, is a being specially
created by Allah to remind people of their weaknesses.