A Versatile
Organ: The Spleen
Another
wondrous element of our defence system is the spleen.
The spleen is made up of two parts: red pulp and white
pulp. The fresh lymphocytes produced in the white
pulp are first transferred to the red pulp and then
join in the blood stream. A detailed study of the
operations carried out in this organ, which is dark
red in colour and located high up the abdomen reveals
an extraordinary picture. Its quite difficult and
complicated functions are what make it so wonderful
and extraordinary.
The duties
of the spleen, such as contributing to cell production,
phagocytosis, conservation of red blood cells, and
immunity construction, are at least as important as
they are difficult. Certainly, the spleen is a lump
of meat just like all our other organs. Yet it displays
a performance and a degree of intelligence unexpected
from a lump of meat. It organizes everything, not
allowing any problems to occur, and works without
rest. Indeed, the spleen works strenuously for the
human from the moment of his birth, and continues
its function as long as God wills.
Cell Production
The bone
marrow of the baby in the mother's womb is not entirely
able to fulfill its function of producing blood cells.
The bone marrow can perform this function only after
birth. Would the baby be anaemic in the meantime?
No. At this stage, the spleen comes into play and
takes control. Sensing that the body needs red blood
cells, thrombocytes, and granulocytes, the spleen
starts to produce these cells in addition to lymphocytes,
which is its main duty.
The spleen,
however, is an unconscious lump of meat. It is not
capable of assuming such a responsibility. Besides,
even if it did, how would it be equipped with the
required information and components to produce the
extremely complex cells and proteins? God, Who created
the human body, created the spleen in such a way as
to enable it to take on other responsibilities in
addition its own task when necessary, and equipped
it with the necessary stimulus and production systems.
Phagocytosis
The spleen
contains a large number of macrophages (cleaner cells).
These engulf and digest old and damaged red blood
cells, some damaged blood cells and some substances
that are carried to the spleen through the blood.
There is a very important chemical recycling system
at work here.
The
macrophage cells in the spleen convert the haemoglobin
protein, which is found in the composition of the
red blood cells they have engulfed, to bilirubin,
a bile pigment. Then, the bilirubin is released to
the venous circulation and sent to the liver. In this
form, it can be discharged out of the body along with
the bile. However, the iron molecule found in the
bilirubin which is about to be discharged out of the
intestines along with the bile, is a rare material
which is very valuable for the body. For this reason,
iron is absorbed back in a certain region of the small
intestines and from there, it first goes to the liver
and then to the bone marrow. Here, the purpose is
both to discharge the bilirubin, which is a harmful
substance, and, at the same time, to regain the iron.
The bilirubin
balance is crucial for our body. This is because even
the slightest problem in this system would lead to
serious outcomes. One of the best examples is that
when bilirubin goes above a certain level, jaundice
develops in the body. However, the cells in our body,
as if they are aware of this danger, discharge the
harmful materials from our body with a great precision
while they select the useful ones among them and put
them into use once again.
Red Blood
Cell Storage
The skills
of the spleen do not end here. The spleen stores a
certain amount of blood cells (red blood cell and
thrombocytes). The word "store" may conjure up an
image of a separate compartment in the spleen that
can be used for storage. The spleen, however, is a
small organ, and it has no space to use as a storage
room. In such cases, the spleen expands to make room
for red blood cells and thrombocytes. A spleen enlarged
due to some diseases may also have an enlarged storage
space.
Contribution
To War
When a microbial
infection or any other malady develops in the body,
the body mounts a defensive attack on this enemy,
prodding the warrior cells to multiply. At such moments,
the spleen enhances lymphocyte and macrophage production.
Thus, the spleen also participates in the "emergency
operation" that is launched at times when disease
could harm the human body.
Another
Production Centre: The Lymph Nodes
In the human
body, there is a police force and a police intelligence
organization scattered throughout the body. In this
system, there are also police stations which have
policemen on guard, and which produce new policemen
when required.
This system
is the lymphatic system and the police stations are
the lymph nodes. The policemen of the system are lymphocytes.
The lymphatic
system as it stands is a miracle performed for the
benefit of mankind. This system comprises of lymphatic
vessels that are diffused throughout the body, lymph
nodes that are located at certain spots on these vessels,
the lymphocytes produced by lymph nodes, which patrol
in the lymphatic vessels, and the lymph fluid circulating
in the lymphatic vessels in which lymphocytes swim.
The system
works as follows: The lymph fluid in the lymphatic
vessels spread throughout the body makes contact with
the tissues located around the capillary lymphatic
vessels. The lymph fluid that returns to the lymphatic
vessels right after this contact brings along some
information about these tissues. These pieces of information
are transmitted to the nearest lymph node located
on the lymphatic vessels. If any hostile action has
started in the tissues, its knowledge is forwarded
to the lymph node through the lymph fluid.
In case any
danger is sensed following the examination of the
nature of the enemy, an alarm is given. At this point,
the rapid production of lymphocytes and some other
warrior cells starts in the lymph nodes.
After the production
stage, the new soldiers are transported to the front
where the battle is fought. These new soldiers will
travel from the lymph nodes to the lymphatic vessels
through the lymph fluid. The soldiers, which are diffused
into the blood stream from the lymphatic vessels,
finally reach the battleground. This is why the lymph
nodes in the infected region swell first. This shows
that the lymphocyte production has increased in that
region.
Now, let us
summarize the system:
- A special transportation
system that covers the length and breadth of body.
- Lymph node stations dispersed
throughout different regions of the body.
- The intelligence operation
directed at the enemy cells.
- Production of soldiers
according to the results of the intelligence report.
It is impossible
for this system, which would collapse in the absence
of even one of its elements, to have originated by
developing gradually over time. For instance, a system
with lymph nodes and lymphocytes, but without lymphatic
vessels, would not be of any use. The system can work
properly only if all its elements are created simultaneously.