Dear Peter! My fellow organs in your body have been telling you about themselves. You have seen that each of them fulfills different special tasks. But did you ever stop to ask where they sit or what they hang on to? Since nothing can float by itself in space, your organs and tissues need a support to settle in their places. When you build a house, you add blinds, ceiling lamps, doors, and windows. Before you install these details, you build the beams and columns, which are called the “framework” of the house. Without this framework, you would not be able to attach any of those details in their place. Similarly, I am a very important system, which provides a shelter for your organs and a support for them to be stable in their places. My skull protects and hides your delicate eyes and brain; I hold your heart, kidneys, lungs, stomach, and intestines in different ways and serve as a barrier against external impacts, and I provide proper places for all your organs to work comfortably. Contrary to your other organs and systems, I seem to have a simpler structure-which consists of bones, cartilages, and connective tissues-but they are all brought together in an appropriate combination and order. The fact that my structure is simpler does not mean I am not a work of art. Indeed, the shapes and structure of each of my bones demonstrate how perfectly designed I am. All of your other organs have been made of very delicate and soft tissues, which could be easily damaged. I fulfill the important task of protecting your brain and sensorium, which are vulnerable to bumps, shocks, drying, and heat. My other important duty is allowing your body to move: my bones are appointed with the task of building a proper lever system, which helps the movement of your legs so that you can walk around comfortably and also helps the motions of your arms and hands so that you can do physical jobs easily.

I consist of 217 bones in your body (however, since the bones in the thigh and sacrum areas fuse together in order to form a stronger bone, their number decreases, and the anatomists accept the number of bones as 206). I have 22 skull bones, 33 spinal bones, 24 rib bones, 64 bones in the hands, the forearms, the arms and the shoulder girdle and 66 bones in the feet, the legs, the thighs and the hip area. In addition, I have 6 small ear bones, 1 breastbone and 1 hyoid bone (at the root of your tongue), which make up the total of my 217 bones. It is quite amazing that so many different bones have cooperated with each other and contributed to such a perfect system.

Each piece of my skeleton has been created with special shape and quality that is proper to its place and duty. The bones that protect your brain are flat, whereas the bones in your arms and legs are long and cylindrical; while the bones in your wrists and ankles are short and rounded, your hips and girdles have been made of wide and big bones. The craggy surface of my bones makes it easy for the muscles to attach to them firmly. Each bone has certain durability that protects me from undue weight, flexure, twisting, and pressure. Bioengineers carefully examine my bones that have been created in a perfect form for where they are positioned and for what they do. They take my wonderful structure as a model, and they use it for producing new technology such as buildings or bridges. As you know, constructional engineers have to be very careful in their estimates of material and durability. They have to use different materials for different places, and these points will be exposed to forces like pressure, compression, tensile, or flexure (bending). If the estimates of the materials are not made accurately, the building or the bridge can easily collapse. When you humans build a strong building, it might be too heavy and bulky, resulting in a waste of material and money. Even if you use good quality material, if you do not use it in the right place, all your work might be unusable. Unlike human beings, the Creator has made me such a delicate and well-balanced system, in which you cannot find any material missing or unnecessary or any wrong line in a particular bone. That can only be explained with the boundless knowledge of God the Almighty. He knows exactly how you will be able to do hundreds of different movements in all your life-including running, lying down, jumping, lifting a heavy item, playing sports, writing, and eating. In order to allow you to perform those actions, He has created a perfect design for each piece of my bones and the joints that connect them.

In building my structure, He has used materials in different hardness and durability to make your movements easy. The first material is the bones. Not all bones are the same. Compact bone (dense bone) is found in my hardest parts. For example, the long bodies of the femur, the tibia, and the fibula (bones between knee and ankle) are made of compact bone, and they are very rigid and strong. Softer bones, which look like a sponge, are found at the edges of those long bones and within my flat bones. The second material, my cartilage, is placed at the bone edges and on the joints where, by absorbing excessive pressure, the cartilages are able to prevent damage to the surface of joints and to the nerves that go through the vertebra. My cartilages achieve this thanks to their soft and flexible substance, which also provides a perfect aesthetical quality. In addition, because of this flexibility given by God, cartilages protect the bones from breaking easily (depending on the rigidity of the bones), and they balance your strong and abrupt movements. If it were not for the cartilages on the joints, not only the bony surface would be damaged but also my movements would be mechanical and harsh just like those of a robot. My third material is the ligament, and its main substance, the fibers, that are made of collagen protein. The fibers of this ligament are very strong straps, which hold my bones and cartilages together.

All my joints and tendons that fasten the muscles to my bones are tied up and strengthened by those ligament fibers, which vary in shape, length, and quality. The collagen fibers are also used as the basic substance of my bones and cartilages. Those fibers, which are placed among the cells of the tissues of my bones and cartilages, provide the tissues with strength and durability. The distribution of the fibers in my bones is determined according to the direction and intensity of the pressure coming upon me. To see an example, you can look at the head of my femur (between my knee and thigh) where it makes a joint with the thigh bone. The spread and design of the fibers placed right at this joint requires a flawless calculation, which you can better understand by examining a diagram of it.

Not all my joints are flexible in the same degree. For example, the joints in your skull, which protects your brain and sensorium, resemble the toothed blade of a saw. They are strong joints, which are firmly locked with each other, and they allow no mobility. Of course, it can be no one but God who is able to give my skull such strength and hardness, since He knows exactly how much protection my delicate brain, eyes, and ears need. Moreover, my skull is not shaped simply as a bony capsule; at certain places, God has put little channels for the blood vessels to go through, little cavities for the sensory organs, and a big hole for the spinal cord to connect to the brain. Can any of these be formed by coincidence? The joints between the vertebrae (little bones of your spine) are more movable than the skull and less movable than your fingers. They help to allow you stand upright and sit, twist, and bend or lie down. The joints in my shoulders and legs are freely movable, which enables you to do movements in all directions. Perhaps the most wonderful of all are the joints in your hands! It would not be a distortion to say that-behind all your work to make a discovery or an invention or a new technology-is the skillful creation of my hand joints. Everything that you use with your hands-including all kinds of tools, furniture or appliances, art works, and books-can be produced or utilized only through the perfect ability of my joints to move. If my fingers lacked that great ability to move freely, many of my thoughts or intentions would not be able to be translated into actions.

Your muscles that help in the movement of all my movable parts have to attach to my bones to be supported. While one end of your muscle holds my bone firmly, the other end pulls another bone with the help of the joints. That is how movement in your body occurs and how you can take a step, do exercise, or wave your hand.

Although not as much as the skin, I have a very good ability to renew myself. When one of my bones is broken, if you line up the two pieces exactly in relationship to each other, the bone cells, called osteoblast, quickly divide to produce new cells, fill the gap, and repair the break. Then, I take calcium salts, which harden and strengthen the area, and gain back my health. Calcium is a vital mineral in the growth of bones. When you are a little but growing fetus in your mother’s womb, you need plenty of calcium for your bones to develop. If your mother gets sufficient amounts of dairy products, fish, and green vegetables, there will not be a calcium deficiency. But the good news is that, even if an expectant mother does not get enough calcium, the unborn baby is unlikely to have calcium deficiency. That is because Our Lord God, whose Mercy is infinite, provides baby with calcium by making it be absorbed from the mother’s bones and teeth and ensures the healthy development of the baby’s tiny skeleton. The mother has the willpower to feed herself, but since the baby is helpless, its need is met by the calcium taken from the mother’s body. After birth, the baby has to be nourished well with calcium and vitamin D by means of healthy foods, and it has to have enough exposure to sunlight. In order to maintain my health, my biggest need is calcium salts and vitamin D, a vitamin that needs the body’s exposure to the sun in order to contribute to healthy bone growth. For this reason, you have to take care of me especially at your young age. If you do not get those salts and vitamins, your bones will not develop well, and this could result in skeleton disorders.

The cavities within my bones are called marrow cavities (or medullar space) and they have important duties too. If your bones were filled merely with bony substance, my weight would be too much, and you would not even be able to stand up. Moreover, my bones would not be as strong as they are now. According to calculations with static forces, a rounded iron stick, which is filled, is less durable than the one with a hole in it, and the stick with a hole in it can be bent easily. My long, rounded bones have been designed according to that principle, and they are more resistant to twisting and bending. Another important function of my marrow cavities is to house the production of little red blood corpuscles, which have important duties within the blood. When you are young, all my bone marrows are red, and they produce red blood cells. Then, slowly after the puberty, the bone marrows in my long rounded bones start to turn yellow, get fatty, and produce white blood cells. The spongy bone marrows in my flat bones, however, stay red in color during your entire life, and they keep producing red blood cells.

The shape and size of my bones and their proportions to each other all determine the shape and quality of your body. Although I develop according to my genetically inherited qualities, the loads that you made me carry and outside impacts all affect my development significantly. When you are a baby, my bones start out as cartilages. At young ages when I am just starting to become bony, if I have to carry too heavy things, I start to harden and become bony too fast. This leads to the incomplete growth of the length of your neck bones, and your arms and legs which will remain too short. Playing basketball or volleyball stimulates the growth and elongation of your bones. Mineral salts, vitamin D, and the hormones secreted by the parathyroid gland play role in the ossification of my bones. The elongation of my long bones is achieved by the cell division and formation of new cells in the areas called epiphysis, which are the rounded ends of the long bones. This bone-lengthening process ends after puberty. While the lengthening of bones stops earlier in girls around ages eighteen or nineteen, it continues in boys until the ages twenty-one or twenty-two, which is the reason why men are generally taller than women.

When you were born, all of my components were cartilages, which are very soft and flexible. That is the measure that the all-knowing and all-caring God has taken, to ensure that neither you nor your dear mother gets any harm during your birth. If I became bony before the birth, your mother could die, and many of your bones could break during the birth. However, thanks to the cartilaginous components, which are like plastic, the risk of death and becoming disabled decreases greatly. As you become older, the cartilages are replaced with bone cells, and the accumulation of calcium salts make me hard and bony. The cartilages remained only on the joint surfaces and at the ends of ribs.

Dear Peter! Now it is time to ask a question that might bother you a little: have you ever been at a reopening of a grave? Sometimes in graveyards, when they do not have extra space for new burial, the dead person’s body is buried next to a body that belonged to a family member. When the grave is reopened, you can clearly see that, except for the newly buried body, all parts of the other dead body have been mingled with the earth. You can see that only my skull and other bone components have remained without decaying. After a very long time, those bones will decay too but much later than my other tissues. In the past, when the Holy Qur’an was just being revealed, some people refused to believe in God and the Day of Judgment, and asked: “Who is going to resurrect those decayed bones?”(Qur’an 36:78). The following verse is an answer: “Say, ‘He who created them in the first place will give them life again: He has full knowledge of every act of creation’” (Qur’an 36:79). In many other verses of the Qur’an, which deal with both the first creation and the Judgment Day, also mention decayed or dried bones, which still exist after many years. This means that God wants to draw your attention to the bones of your body! Perhaps, He is saying: “O, Peter! I created your bones, your joints, and your whole skeleton flawlessly. I took all measures for you to be able to live your life perfectly; to the littlest details, I created a delicate body, mind, and soul free of defects or faults. When I created you that perfectly, do you think I took something else as a model, or applied someone else’s plans? Not at all! Therefore, I, who created you out of nothing with my infinite knowledge and might, will of course be able to recreate you!”

Well, Peter! That is how I understand my Creator and the message of His Holy Book, which appeals to all of humanity. Your ability of comprehension and appreciation is more perfect than mine. Therefore, each time you move your body or body parts, just think of the wonderful pieces of bone accompanying and supporting your organs. Reflecting on them for some time will gain you a fresh view of life. That is what I wish as your skeleton!

Irfan Yilmaz is a professor of biology at Dokuz Eylul University, Izmir, Turkey.