Introduction

Dear children, prepare yourselves to step into a broad and miraculous world in a little while. In fact, this world interests you closely. Although you might not have realised until now, trillions of workers of this world have been unceasingly working for you. You are surprised, aren't you?

Our bodies are composed of cells, each of which has assumed a different task. The figure below shows a few types of our body cells, which act together to enable us to live.
I.Structurel Connective Tissue Cell, II. Fibroblasts,   III. Cartilage Cells,  IV. Bone Cells,	V. Nervous Tissue, VI. Epithelial Tissue, VII. Stomach Cell, VIII. A Type of Kidney Cell,	IX. A Type of Kidney Cell, X. Muscle Tissue, XI. Heart Muscle Cell, XII. Skeletal Muscle Cell, XIII. Smooth Muscle Cell

This marvellous world is your body and the workers which have been working for you are your body cells. Every point of your body consists of cells. At this moment, there are trillions of cells in your body that are at your service. They are working even while you are reading this book. For example, your eye cells are carrying out a number of processes ceaselessly in order to enable you to read. As you breathe, the cells in your windpipe and then the cells in your lungs come into play. In the meantime, the cells in your stomach are probably digesting the food you ate a few hours ago.

SECRETORY CELLS
AND OUR CELLS GO UNDER THE MICROSCOPE......
CELLS iN THE EYE	NERVE CELL	RED BLOOD CELL

What we have mentioned here are only a few of the processes that are continually carried out in your body. All of these happen without your even being aware of them. How is that trillions of cells come together, know what to do and co-operate to function? Moreover, no trouble arises during these processes. No cell attempts to do another's task or refuses to perform its own task. Besides, all these processes take place with an extraordinary speed.

In the coming pages, we will examine how daily tasks, such as digestion, respiration, seeing and hearing are, in reality, quite splendid. We will witness that our cells sometimes act like a chemist to produce chemical substances, sometimes act like an engineer to make calculations and sometimes work to meet the needs of some other cells.

It is astonishing that all these are achieved by cells that are too small to be seen with the naked eye. Moreover, the cells in our bodies perform these vital functions without receiving any help. Remember that these cells are not human beings like us. They can neither see each other nor hear, nor decide to "do wise work". They have no ears or brains. They have not studied chemistry, but, as we will see in the following sections, they know chemical formulas and can produce substances according to these formulas. How is it that they can do all these?

You will be filled with admiration as you read and find out that cells do not perform all these tasks by their own wisdom. You must already be aware that they could not have possibly learnt how to carry out these tasks in time by chance.

Still, we owe our life to the conscious acts of these tiny beings, which we cannot even see with the naked eye. Surely in them there is a very important fact for us to understand. There is a possessor of superior wisdom who makes our cells perform all these tasks and teaches them what to do. The possessor of this eternal wisdom is Allah, Who has created everything, loves us and knows all of our weaknesses and needs.

More processes are carried out in every one of our bodies' cells, which are too small to be seen with the naked eye, than in the laboratory below.

Each one of the trillions of cells in our body fulfills its tasks perfectly as a result of Allah's perfect plan, so that we may lead our lives without any difficulty. Waking up every morning to go to school, tasting the sweet flavour of honey, breathing without any difficulty, running in your school garden and playing with your friends, writing, reading and lots of other things you do are thanks to Allah's compassion and mercy.

In the picture above, you can see the inside of a cell. At the center of the cell is the cell nucleus, which is surrounded by other cell parts.

I. Nucleus II. Ribosome

Like all other things on earth, Allah has created you perfectly and given you everything you need. What you should do in return is to give thanks to our Lord, Who has given you all these blessings that are much more valuable than any other present you may be given in this world.

For this reason, we need to think thoroughly about what Allah has bestowed upon us. In the verses of the Qur'an, our Holy Book, Allah has given many examples for people to reflect on. The following is one such verse:

In the creation of the heavens and earth, and the alternation of the night and day, and the ships which sail the seas to people's benefit, and the water which Allah sends down from the sky—by which He brings the earth to life when it was dead and scatters about in it creatures of every kind—and the varying direction of the winds, and the clouds subservient between heaven and earth, there are Signs for people who use their intellect. (Surat al-Baqara: 164)

In this book, we will reflect upon our bodies. We will see how perfectly and elaborately the human body has been created by Allah. Once you read the book, you will love Allah even more and thank Him. You will be surprised at the neglectfulness of the people around you, who do not reflect, and you will be eager to tell them what you know, so that they will be heedful too.

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?

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.

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.

During all your activities throughout the day, your nerve cells are constantly busy.

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.
1. Brain, 2. Spinal cord

Indeed, nerve impulses are active in your body at this exact moment too. Nerves in your fingertips are sending messages to your brain regarding the weight of this book that you are holding in your hand, 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.

The cell on the right with the fringe-like extensions is a nerve cell (neuron). Billions of nerve cells, interconnected through these branches extending out from the cell body, form a network right through the body. There are gaps between nerve ends, and nerve signals are carried across these gaps to other nerve cells.

I. Dendrites,
II. Nucleus,
III. Nucleolus

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.

HOW DOES THE BRAIN FUNCTION?

Scatter puzzle pieces irregularly on the floor and suppose they are the entire knowledge about the world. For instance, let some pieces represent light, some represent colours and yet others represent sounds. Now take these pieces one by one and start reassembling them to form the picture. What you can do by thinking it over at length is done hundreds of times in a second by your brain, which works by Allah's inspiration. Do you wonder how?

The brain gathers the information received from the eyes, nose, ears, skin, mouth etc. and construes them. What makes this interpretation is a collection of 100 billion nerve cells in your brain. These cells operate unceasingly and enable you to see the colour of the apple you eat, to recognise the voice of your best friend and to perceive the smell of hot chocolate.

1-Taste  2-Speech  3-Motion  4-Touch  5-Smell  6-Sleep
7-Hearing  8-Sight  9-Balance

The picture on the next page shows some children who are talking, hearing, smelling, moving and sleeping in the brain. Of course this is an imaginary picture, intended to show the particular portions of the brain and their functions. In reality, what the brain consists of is nerve cells, which can be seen only under a microscope. Do you think nerve cells can see your favourite toy or taste the flavour of chocolate ice cream? Certainly not. That is because nerve cells are composed of fine pieces of flesh. Hence there must be another being with supreme power who created this wonderful world. This being is Allah. Allah, the possessor of everything, creates everything perfectly and presents each of us with a beautiful life. What we should do in return is to be thankful to our Lord. Allah has given our eyes and ears as an example, and has told us to give thanks for them to Him:

It is He Who has created hearing, sight and hearts for you. What little thanks you show! (Surat al-Muminun: 78)

The Journey That The Food We Eat
Makes in The Body

W e obtain the energy needed for bodily functions from various foods and drinks. However, every food that we eat, for example pasta, the meat or the banana, needs to be digested first in order to be ready to be used in the body. These foods are used by body cells after they are digested. The sugar contained in a banana or in an apple provides fuel for your cells and increases your energy; the proteins contained in meat are essential for the growth of your cells, and thus of your body. Try to get back to your infancy now.

AGE 1	AGE 7	AGE 11

You were approximately 2-3 kilograms (4,5-6,5 pounds) when you were born. Your weight will increase to 30-35 (65-75) when you are 10, to 40-50 kilograms (90-110 pounds) when 15 and 50-60 kilograms (110-130 pounds) when 20-25 years old.

The reason for this huge difference is the fact that the substances in the foods you consume are added to your body in time. Some of these foods provide the energy you require to ride your bicycle, to run and to play, whereas some are added to your body and constitute your flesh and bones. Waste matter is discharged from the body. All these processes are performed in your digestive system. Organs and glands including your stomach, intestines and pancreas have roles in digestion.

The Total Length of The Digestive Tract, Starting from The Mouth To The Intestines, is 10 Meters (30 Feet). 1- Salivary glands secrete saliva, which starts the breakdown of starches. 2- Food begins as complex carbohydrates 3- Carbohydrates are broken down into simple sugars. 4- Glucose goes to the liver. 5- Insulin tells the liver to store glucose as glycogen. 6- The liver stores some glucose as glycogen. 7- Glucagon tells the liver to change glycogen into glucose. 8- When blood sugar is low, the pancreas sends the hormone glucagon to the liver. 9- When blood sugar is high, the pancreas sends the hormone insulin to the liver. 10- Some type of enzyme is secreted by the pancreas into the beginning portion of the small intestine. 11- In the beginning part of the small intestine, this enzyme cuts down carbohydrates into simple sugars. 12- Glucose is absorbed into the bloodstream.

The functioning of the digestive system is similar to the working of a petroleum refinery. Crude oil arriving at the refinery as raw material is processed by machines and refined so as to be usable. The foods that we eat are raw materials in the first stage and are then processed in the stomach so as to be used by the body. Having been broken down in the stomach and the intestines, foods become ready to be used as the nourishment of the cells and are conveyed to relevant regions of the body via blood vessels.

A single parent substance is processed in a petroleum refinery and a variety of products, for example gasoline, which is a fuel for automobiles, or the rubber used as the sole of your shoes, are derived from it. Likewise, the nutriments in the foods are broken into fats, sugars and carbohydrates in the stomach. But remember that what happens in your stomach after you eat a delicious sandwich is even more complex than what happens in a refinery. Moreover, this series of actions which we will soon discuss does not take place in a gigantic factory, but in a very small region in your own body.

The total length of the passage through which food is digested is 10 meters (30 feet). This is 6-7 times the average human height and it is marvellous how such a length is fitted into our bodies. How is it that such a long canal has been placed in a human body? The answer to this question reveals once again that there is a special design in the creation of our bodies.

Since the digestive tract, as you can see in the picture on the left page, is coiled up, it is fitted into a very small area, despite its length. This special shape is the perfect design of our Lord, Who created everything. This feature of the digestive system is only one of the wonders that Allah created in our bodies.

Do you know why your teeth have different shapes?

The reason why they have different shapes is that each has different tasks. For example your front teeth are sharp, so you can bite an apple easily. What if the molar teeth were in the front? Yes, you are right. You would not be able to bite a piece off the apple with your molars. Likewise, if your front incisors were at the back, you would not be able to grind the food you eat. As in every single part of your body, the teeth in your mouth are also arranged by Allah in the most convenient and advantageous order for you.

Beneficial bacteria live at the back of your tongue

Bacteria are generally known to produce diseases and, to be protected from their harmful effects, people should be careful about the cleanness of both their bodies and the environments they live in. However, not long ago scientists discovered the presence of some beneficial bacteria in the human body, particularly at the back of the tongue. Yes, you've read it correctly; there are beneficial bacteria in your body. The duty of the bacteria behind your tongue is to kill the harmful microbes in your stomach. But surely this is not an easy task and it demands a series of actions. First of all, bacteria convert the nitrate found in green-leafed vegetables like lettuce into nitrite. However, the process is not over yet. Nitrite, in combination with the saliva secreted in the mouth, has an antimicrobial effect. In other words, the bacteria behind your tongue help in the production of a microbe-killing substance. As you know, microbes cause various diseases. Thanks to the beneficial bacteria that produce a microbe-killing substance, you are protected against many diseases. These beneficial bacteria are one of the manifestations of the compassion of our Lord, Who created our bodies in the most perfect way. Allah has given us many beauties and gifts. That these gifts are innumerable is related in a Qur'anic verse as follows:

If you tried to number Allah’s blessings, you could never count them. Allah is Ever-Forgiving and Most Merciful. (Surat an-Nahl: 18)

How Does The Stomach Digest Food?

Now let's make a more detailed examination of the process of digestion. Consider breathing, swimming, riding a bicycle, eating… These are parts of our everyday lives, yet most of the time we do not even think how they occur. Our bodies need energy. We have already explained that we obtain this energy from the food we eat. But the nutriments required by the body should be simple and in particles small enough to pass through the blood vessels. Otherwise they cannot permeate the cells. However, the foods we consume are in large pieces. Therefore, we need a machine to enable the body to use the food we eat. In fact, we may briefly call this a grinder, which basically reduces the food we eat to smaller particles. This grinding machine in your body is called the "digestive system".

This system, like all machine systems, is composed of various components and thanks to the perfect functioning of each of these components, we can digest food. It is vital that components of the digestive system be harmonious and complete because the whole system fails unless they are so.

Now let us give an example to illustrate why all the components of a system should be complete for the proper functioning of the system:

A remote-controlled car is composed of parts such as wheels, a controlling device, motor, batteries, gear, coil, antenna, etc. Likewise, the digestive system is composed of various components. These include the teeth, tongue, oesophagus, stomach, and intestines.

 

In our bodies, there is a lifesaving gate: the epiglottis which is situated at the top of the windpipe. This flap covers the opening to the air passages when swallowing, preventing food or liquids from entering the windpipe.

 

I. Epiglottis open,   II. Epiglottis shut.

Now think. Would a remote controlled car operate if it did not have antenna or wheels? Of course not. The car can run only if all of its parts are present. The same applies to the digestive system. The presence of the stomach would be meaningless unless there were also an oesophagus, since what carries food to the stomach is the oesophagus. In like manner, intestines cannot possibly be of any use unless there is a stomach, because the foods digested in the stomach are passed into the intestines, where they are given the proper form to be conveyed to body cells.

This clearly shows us that our Lord, the Creator of everything, created for us a system that is perfect in every way. This reveals once again that there is no other god than our Lord:

Your god is Allah alone, there is no god but Him. He encompasses all things in His knowledge. (Surah Ta Ha: 98)

The Digestive Machine Starts Working...

Digestion starts in the mouth. Carbohydrates in the foods you eat are first broken down into smaller particles by the saliva in your mouth. For instance, the bread you ate at breakfast started to be broken down initially in your mouth. But it will take longer for the cheese you ate along with that bread to be broken down.

 

stomach

 

gall bladder

 

peas

 

small intestine

Nutriments broken down in the mouth pass through the oesophagus and reach the stomach. In the stomach is another marvellous state of equilibrium. Digestion of foods in the stomach is performed by a very strong fluid. This fluid is hydrochloric acid.

That is Allah, your Lord. There is no god but Him, the Creator of everything. So worship Him. He is responsible for everything. Eyesight cannot perceive Him but He perceives eyesight. He is the All-Penetrating, the All-Aware.
(Surat al-An'am: 102-103)

As you know, acids are corrosive materials. They are capable of dissolving what they are in contact with. For instance, what your mother uses to clear an obstructed plug hole contains acid. Breaking down dirt and waste matters that blocked the pipe, these acids rid it of obstructions. It is thanks to the strong acid found in the stomach that the foods, which are in large pieces when they first arrive the stomach, are broken down into smaller particles that can be used by the body. Yet there is one more point that needs to be noted.

INNER STRUCTURE

Different types of stomach cells secrete different secretions to digest the foodstuffs we eat.

I. Stomach, II. mucous surface cells, III.Gastric Pit, IV.mucous surface cell (secretes mucus) V. mucous neck cell (secretes mucus) VI. parietal cell (secretes hydrochloric acid and intrinsic factor) VII. chief cell (secretes pepsinogen) VIII. hormone-producing G cell (secretes gastrin)

We have mentioned that the food eaten is broken down into pieces by the stomach or gastric acid. So how is it that this acid does not destroy the stomach itself, which is also made of flesh? Now, think about it. The gastric acid digests the meat, for instance, you eat at dinner, yet ignores the stomach, which is in the same way a piece of meat. Why is this so? At this point, the excellence in the creation of our Lord is revealed once again. Allah, Who created everything perfectly, designed a protection so that the stomach itself is not digested.

This protection may be summarised as follows; another fluid, namely "mucous", is secreted during digestion to prevent the hydrochloric acid from breaking down the stomach. A special mucous layer covers the inner lining of the stomach and protects the stomach from damage by this powerful acid. So the stomach does not digest itself.

The next place on the digestive route is the intestines. Nutriments are broken down into even smaller particles and are made usable by the body as they pass through the two intestines, the large and the small. What is useful in these nutriments is introduced into the bloodstream and the unnecessary residue is discharged from the body by the excretion system. The phases that the food eaten passes through in the intestines are also very important. Digestion continues in the intestines as in the stomach. Nutriments are broken into even smaller particles. They are now so small that they are absorbed by the blood vessels around the intestines and are involved in the bloodstream to be carried to every part of the body.

Children, you must have realised that the digestive system is planned completely and perfectly. During this journey, which starts at the mouth, proceeds along the oesophagus, the stomach and the intestines, the food eaten passes through several phases. And finally the nutriments that our body cells require are obtained. These are absorbed in the intestines and delivered to the body via the bloodstream. Digestion of food would be very hard if this mechanism did not work so perfectly.

Stomach One function of the stomach other than digestion is storage: Foods that reach the stomach are kept here for a period. Then they are little by little passed to the small intestine for further breakdown. If the foods you ate were not stored in your stomach, you would have to eat every 20 minutes because your stomach would always be empty and you would feel hungry all the time.

First of all, if we lacked teeth, we would not be able chew our food sufficiently and it would not go down the throat. Even if it did, it would seriously injure the oesophagus. If our stomach were not able to digest the food, everything we ate would remain as a large mass in the stomach, which would be quite disturbing. Besides, as a result of not being able to digest foods, our bodies would not be provided with the nourishment they require. An unnourished body loses its strength after a while and body cells start to die. But we do not experience such things, because our Lord created every single part of our bodies perfectly. This excellent system runs flawlessly, and we are quite unaware of it. This excellence in creation is related in the following verse:

He is Allah – the Creator, the Maker, the Giver of Form. To Him belong the Most Beautiful Names. Everything in the heavens and earth glorifies Him. He is the Almighty, the All-Wise.(Surat al-Hashr: 24)

The Blood’s Journey Through
The Veins

In previous chapters we referred to a gigantic network of nerves running right through our bodies. There is another such miraculous network. This consists of blood vessels. Like the network of nerves, blood vessels, too, circulate through the body. They are so long that their total length would be about 100,000 kilometres (62,000 miles) if they were spread over a flat surface. In fact, it is not hard at all to understand that there are blood vessels all around our body. Even a small scrape on any part of our body would start to bleed immediately. This proves that blood circulates all through our body. It is vital that we have blood vessels at every point because, as mentioned in the previous chapter, the nourishment required by the body cells is conveyed through the blood vessels. Oxygen that cells need for proper functioning is also carried to cells by the blood flowing through our veins.

transporting freight by ship. Prior to shipment, first of all goods are placed upon the ship at the port. Goods should be properly packaged and placed. After all are loaded, the ship sets out and heads for the port of its destination. When it arrives at the port, all packages are unloaded and distributed to the concerned sections. In the blood vessels, nourishment is similarly transported to cells, just as ships transport cargo across the ocean. Oxygen, fats and amino acids flow in the bloodstream in packages and are unloaded at the target cells. This transportation schedule never fails. Proper amounts of required substances are conveyed to relevant cells just on time. Otherwise, for instance, if a cell that needed oxygen received fats instead, this cell would die. It should be noted that even the slightest mistake in this system could result in serious harm. Such mistakes never happen except in unusual cases, however, because none of these came into existence by chance. Allah, the Creator, created this system perfectly for our service.

What is in The Blood?

As blood circulates all through the body, it fulfills many tasks. Now let's have a brief look at these tasks.

Transporting Cargo  

We have already explained that all the kinds of substances that our body needs are conveyed to the concerned organs by blood. In the meantime, blood cells collect waste matters, like carbon dioxide, and make sure that they are discharged from the body. In a way, blood acts like a garbage grinder. Stopping by each of 100 trillion cells again and again throughout the day, it leaves the cells what they require and at the same time collect what is not needed.

There are different types of cells in the blood, each of which performs a different task. As seen in the picture above, some of these cells carry food while some others defend the body like soldiers.

Blood, which is merely a fluid, can faultlessly perform a task demanding such attention and responsibility. It knows each of the substances it carries, what it will be used for and to where it should be delivered. For instance, it does not mistakenly convey to a cell the carbon dioxide it has taken from another cell as a waste product. It always supplies cells with oxygen and removes carbon dioxide. Blood performs this task with no mistakes or fatigue, because it is a part of the perfect plan that Allah created in the human body. As they unconditionally surrender to the system created by our Lord, all blood cells perform their tasks without making any mistakes.

As seen in this picture, bacteria or microbes entering the body are seized , engulfed, and thus inactivated by warrior cells called macrophages. I. Macrophage, II. Bacteria, III. Blood cell, IV. Blood vessel

Soldiers in The Blood

Everyday our bodies struggle against many bacteria, viruses and microbes. Some are prevented from entering the body, while some manage to enter. But there are special defence cells in our bodies to fight against them that are called immune cells. These cells, which are like soldiers fighting against the enemy and protecting our bodies from dangers, move in the bloodstream. Whenever there is an enemy attack, they can reach the related part of the body through the blood vessels and easily fight against the enemy. Immune cells have not learnt their missions on their own. They have known them since they came into being. They start performing their duty and protecting the body the minute a baby born. This is an excellent detail in Allah's creation. Our Lord has taught cells which cannot be seen with the naked eye very important knowledge and placed them at our service.

Communication

Blood also serves as a means of communication in the body. There are messengers in the blood taking messages from one part of the body to another. These messengers, known as hormones, transport messages to the relevant organs like a postman delivering mails. Many significant processes, including the growth of the body, thirst, perspiration and control of blood sugar levels are thanks to such precisely delivered messages.

As seen in the picture above, hormones travel through the bloodstream with the messages they carry and deliver these messages to the relevant organs. I. Hormone receptor, II. Hormone, III. Cell membrane, IV. Blood capillary, V. Cell nucleus, VI. Hormone receptor, VII. Blood capillary, VIII. Hormone I. Macrophage, II. Bacteria, III. Blood cell, IV. Blood vessel

Blood That Heals Wounds

You must have observed that a slight skin wound stops bleeding spontaneously after a little while. This, in fact, is quite thought provoking since, under normal conditions, a liquid flowing from a hole cannot possibly stop flowing of its own accord.

To have a better understanding of this fact, suppose that you have a balloon filled with water. If you make a little hole in this balloon using a needle, water will leak out of the balloon. Will it stop leaking after a while with no intervention of yours? Of course not. All the water will keep leaking until the balloon runs out of water. This applies to all liquids in closed spaces.

Blood moves through a closed circuit of veins and leaks out in case of even a slight cut. However, it is of great importance for our health to stop its flow. You may have heard of people who die of excessive blood loss in accidents or operations. Well then, what causes blood to stop flowing a little while after a wound starts to bleed?

This is called blood clotting, which is one of the automatic security systems in our bodies. Some substances existing in the blood stop and close the wound. Thanks to the clotting ability of blood, excessive bleeding is prevented. As shown in the illustration on the right, some cells in the blood are informed of the damaged vein and head for that site at once. First they align themselves along the wound and obstruct the flow of blood by weaving a web. This web stiffens in time and forms what we call a scar.

Left: A CLOT FORMS Platelets release chemicals that make fibrin. The thread-like fibrin traps platelets and red blood cells (bottom). Aclot forms, which stops the bleeding. Center: BLOOD TO THE RESCUE Injured cells signal for help. Platelets stick together to plug the wound. Right: ATOUGH SCAB  The fibrin, trapped cells, and fluid from the blood harden into a protective scab. Healing begins.

Now let's think together. Can this planned series of actions take place by chance? How is it that some blood cells are informed of damage somewhere in the blood vessels, which is like a gigantic world in relation to their size? Why do they strive to prevent the flow of blood? How do they know that they should close the wound in order to stop loss of blood? Who taught these cells that they should close the wound?

Blood leaks through the wound.. I. Red blood cell, II. Platelet, III. Damaged skin

Blood surrounding the wound coagulates.

Cells close up the wound like a plug. IV. Blood clot

A cut on your hand or a wound on your knee heals in a short time. The pictures below show some of what happens in your blood vessels during this healing process.

Cells could neither have learnt all these things by chance nor could they have accomplished them on their own. Even human beings, who have intelligence, cannot possibly originate such a detailed system and teach cells what to do. Certainly, the intelligence demonstrated by these cells does not belong to them. Allah inspires them and they act according to a perfect plan.

Allah informs us of the excellence in His creation as follows:

He created the seven heavens in layers. You will not find any flaw in the creation of the All-Merciful. Look again—do you see any gaps? Then look again and again. Your sight will return to you dazzled and exhausted! (Surat al-Mulk: 3-4)

In the picture above, you can see the red blood cells stuck among the fibers of a blood clot. It is thanks to the clotting ability of blood that it stops flowing soon after you are injured.

A Miraculous Fluid with No Reproducible Equals: Blood Scientists have conducted many studies in order to produce a fluid similar to blood. However, having failed to do so, they gave up trying to imitate blood and focused on research in other fields. Scientists cannot imitate blood because blood samples withdrawn from a blood vessel clot at once and the structure of the blood becomes unfit for examination. It does not work to preserve the samples in glass test tubes either, because blood cells do not completely survive in tubes. Therefore, scientists had to separate cells in the blood and examine them individually. Undoubtedly, it is one of the most unreasonable and illogical explanations in the world to claim that such a perfect substance, which cannot even be imitated with all the information human beings have gathered for years, came into existence spontaneously and by chance. Allah created blood as a matchless substance. A blood cell that has many amazing abilities is merely one of the manifestations of Allah's infinite wisdom in the human body.

The Motor of The Body: The Heart

Have you ever thought how litres of blood circulate unceasingly through our body up and down? Every object needs a motor for continuous motion. Cars, aeroplanes, motorboats and even your remote-controlled toy cars move by means of motors. Likewise, blood circulating through our body needs a motor too. The motor that propels our blood night and day, for months and even for years is our heart.

Place your fingers on your wrist and wait for a while. You will feel the beating of your heart. Your heart beats 70 times in a minute, and pumps some 152 million litres (40 million gallons) of blood throughout your life. That much blood is an approximate equivalent of the amount 10,000 oil tankers will hold. These figures are astonishing, aren't they? Now suppose that you have to bail a cup of water from one bucket to the other, 70 times a minute. In the end your arm and hand muscles would ache and you would need to rest. However, your heart carries out this task all through out your life and it never takes any rest.

The Most Perfect Pump The most perfectly structured pump in the world is now beating on the left side of your chest. With its marvellous design and unceasing contractions, your heart makes the entire blood in your body complete 1,000 full cycles in a day. The heart is a pump made of flesh, which is approximately as big as one's fist. Nevertheless, it is clearly the strongest, the most durable and the most efficient engine in the world with respect to its capacity. We have many reasons to express the strength of the heart in this way. Most important, the heart uses a great deal of energy when it beats. With the energy used by the heart, blood can be raised up to 3 metres high. It may be helpful to give an example in order to make it easier to comprehend the heart's capacity. In an hour the heart can produce an amount of energy that is enough to lift an average car approximately one metre above the ground.
Your heart is an astonishingly strong muscle. It beats about 70 times in a minute, and pumps 59 cubic centimeters (3.6 cubic inches) of blood at each beat. A heart which beats 2,500,000 times in 70 years pumps some 152,000,000 liters (40 million gallons) of blood during this time. That much blood is the approximate equivalent of the amount pumped into the fuel tanks of 10 Boeing 747 jumbo jets every year.	The fuel tank of a jumbo jet will hold 217,000 liters (71,000 gallons) of fuel when full.

Original Pumps in the Heart

The heart, which is a muscular organ of about the size of one's fist, consists of two halves. There are two pumps in these sections. The left pump, which is stronger, drives oxygen-rich blood to all parts of the body. The right pump is weaker than the former and pumps oxygen-poor blood to the lungs. This transport from the heart to the lungs is over a short distance and is, therefore, called the "small circulation". The former is called the "large circulation".

Blood circulates through the entire body, from the brain to the lungs, thanks to the heart..
1-tissue cells 2-pulmonary artery 3-right atrium 4-left atrium 5-pulmonary vein	6-left ventricle 7-right ventricle 8-aorta 9-large circulation capillaries

Each of these halves of the heart is divided into two further sections. Blood between them passes to the other section through heart valves. These pumps operate unceasingly with a great amount of energy, thanks to which blood circulates through our bodies 1,000 times a day.

The Heart Maintains Itself

Machinery needs routine maintenance. It may be necessary to maintain some machine parts or to replace those that are worn out. Machines need to be treated with oil after a certain period of operation, so as to lessen wearing down by friction.
Like machinery, the heart, which keeps operating all the time, requires maintenance too. However, the heart carries out its maintenance itself; it lubricates itself.

How do you think a heart lubricates itself? The answer to this question is hidden in the creation of the heart. The outer surface of heart is covered by a sac consisting of two membranes. Between these membranes is a greasy fluid. This fluid acts like motor oil and facilitates easy operation of the heart. This self-protective structure in the heart reveals once again how perfect and complete is Allah's artistry in creation.