In the past, the area missing a tooth could be filled by bridge implants by eroding the enamel on neighboring teeth. In cases where there was a large gap or no teeth to use as connectors, removable implants were used. In other words, present healthy teeth would be treated to compensate for the missing teeth; if the number and health of the remaining teeth was not sufficient, removable implants would be produced that gave the “ready to fall out” feeling. The imperfections of this type of implant led scientists to pursue new ideas.

Scientists have tried to fill in missing teeth with artificial roots and with implants mounted over these by mimicking the existing tooth root. This way, there is no need to treat and erode the healthy enamel of neighboring teeth in the gap. These artificial roots, which are positioned into the jaw bone by a surgical operation, are called a “tooth implant.” Modern-day implants are generally composed of two main parts.

One of these is the fixture part which is secured into the jaw bone by screws; the other is the support part (abutment) which mimics the visible parts of the tooth in the mouth. Approximately 3-4 months of curing time is required for the fusion of bone and implant (osseointegration), which is screwed together by a surgical operation. Towards the end of this time, the implant is built over the abutment. The length of time necessary for the implant to integrate with the bone to replace a tooth which can be extracted so quickly is rather noteworthy despite ongoing studies to reduce the wait time and successful attempts to do so.

Employed materials

Even though the main logic for implants is the mimicry of the tooth and the root, the materials utilized are quite variable. The history of such implants goes back thousands of years. The employment of bamboo sticks in tooth restorations could be seen in some civilizations, such as ancient China. Mayans used sea shells, which were recently shown to be biologically suitable as implant material. Maggiolo produced a tooth root by using gold, in 1809. In the beginning of the 20th century, Lambotte prepared implants using materials such as aluminum, silver, brass, copper, and gold.

These newer implant methods have failed because of the insufficient strength of the majority of the materials and the failure to fit into biological tissues. The initial employment of titanium and its alloys in the 1950’s almost opened a new age in implantology and enabled the successful use of these materials up until today. However, these titanium implants, which are considered successful, have a very limited ability to mimic tooth roots:

• Once the implant is in place, for reasons such as aging and improper tooth brushing, tooth gum recession and resurfacing of the bright faces of the implants which mimic the root surface can take place. This leads to undesirable displays. Even though gum recession can also occur in natural teeth for similar reasons, this situation is not as disturbing as with implants. This is because the tooth root color is similar to that of the tooth surface.
• Under normal conditions, implants should be fused to integrate with the bone (osseointegration). Integrated implants are considered successful clinically. A similar case to this bondage, which is unwanted clinically, is the fusing of tooth and bone which can be seen generally in dead teeth and is called ankylosis. Many hardships can be encountered when the tooth that is fused with the jaw bone is required to be removed. The same thing also applies to the implant. If an implant is set to be extracted for a reason, even if just a small amount must be removed, the surrounding jaw bone must be removed as well. However, a natural tooth is not bonded so tightly to the jaw bone, as if the tooth is healthy, it is suspended over the jaw bone through small suspension-like structures. When a tooth is needed to be pulled as a result of trauma or tooth rotting, only these suspensions are detached; thus any damage to the jaw bone is averted. Present efforts to design similar mechanisms for implants have not been successful yet.
• When a disease develops in our natural teeth, we feel pain and take action before it is too late. However, diseases within implants are rarely encountered as pain; generally, when the pain is felt, the implant is already disconnected from the bone and it is lost. Toothache often felt as a strong pain is a blessing granted to us. If the implants were built with pain mechanisms, just like in our natural teeth, we could take action at the beginning of the disease and avoid the time and financial losses.
• Even a healthy tooth, which we think of as immobile, can move via microscopic ligaments for 0.1 mm around its root on a type of pad. The tooth root is created in a perfect fashion to resist the strong chewing power that can be generated from many directions in the mouth through these ligaments, which are wrapped around different sides and which come from different angles. However, these ligaments, which act as a suspension, do not exist in between the implant and jaw bone. Therefore, implants are almost immobile. Even though it may seem like a good thing for them to be immobile and tightly fixed, there may be intense power spots generated on the implant or jaw bone since these forces acting on the implants are transmitted to the jaw bone without being dispersed. Forces densely acting on small areas can lead to fractures of the material, including tiny screws or porcelain plating, and can damage the bone tissue. Investigators once understood that these tiny, suspension-like structures won’t form around the implant, so they engaged in mounting tiny Teflon or spring pieces inside the implant to generate suspension. However, these imitated suspensions failed to resist the chewing forces that can go up to 400 kg at times, and their use was aborted after a short time.
• Teeth can be examined by the method of tapping with small hand tools (percussion). These small impacts cause pain in case of an abscess at the tooth root. By taking necessary actions, the tooth can survive longer. It is impossible to do such determination and diagnosis with implants.

As it is seen, making less successful artificial implants as opposed to real teeth is quite a cumbersome, costly, painful, and time consuming job. Despite all of these imperfections, because of their numerous advantages over traditional implants, the popularity of dental implants continues to increase, and is preferred by dentists and patients. In addition, implants are seen as an inevitable treatment option when tooth loss occurs, and may ultimately provide patient relief in the long run.

Despite progress made in implants, it’s clear that our teeth were created in such a perfect way, down to the very smallest detail, that they cannot be replaced. Science is well aware of the fact that we will never fully be able to replicate tooth structure. Therefore, studies are shifting towards stem cell research. This way, instead of foreign substances, the missing tooth will be compensated as if by planting tooth seeds by using human’s own cells. Nonetheless, the opportunities that are discovered via all these efforts will never replace the natural teeth that were so perfectly created for us.

The findings in mice imply that humans might also possess similar characteristics. This increases the possibility and brings hopes of having a baby even at older ages along with treatments in the future, just like in the miraculous story of Prophet Abraham and Sarah as narrated both in the Qur’an (ad-Dhariyat 51:24-30) and the Bible (Genesis 21:7), showing us one aspect of the possibility and ultimate limits of knowledge and technology that humans can attain one day so that these miracles can become true, though to some extent, with the advancement of medicine.

Bone borne eggs

An interesting study showed an unexpected source of oocytes in the bone. Study by Tilly’s group at the Harvard Medical School in 2004 showed that cells in the bone marrow of mice could be a source of oocytes that are developing in the ovaries [1, 2]. Their first observation was the expression of genes related to egg cells in the bone marrow samples of mice. To test the possibility of bone marrow cells as a source of new oocytes, they chemically generated infertile mice. Treating mice with two chemotherapy drugs called cyclophosphamide and busulfan causes infertility. Once they treated the mice with these drugs, the mice had extensive damage in their ovaries along with an end in new oocyte production in their follicles. Ovarian follicles are spherical aggregations in the ovaries which periodically produce oocytes. Remarkably, when they transplanted bone marrow from female donors, they found a number of oocyte containing follicles (about several hundred). Interestingly, the appearance of those oocytes were rapid and thought to be due to circulating oocytes originating from the bone marrow and developing as they travel through the blood stream. Although they don’t have the evidence that those cells could be fertilized, findings could lead to fundamental changes in the current understanding of the female reproductive system.

Tilly and colleagues also report that bone marrow and blood transplants could also induce the development of oocytes in a genetically infertile mice model (which has a mutation in ATM gene) [3]. This mutant mice lack follicles and developing oocytes and are unable to produce mature germ cells (egg producing cells). Their study shows that bone marrow or blood transplant from healthy donors induces production of oocytes in this mice model. They conclude from those studies that bone marrow could be a source of germ cells to the ovaries throughout adult life. Their findings are somewhat supported by the clinical studies on cancer patients who were expected to be infertile but they could have babies after bone marrow transplant.

Another study on the circulating cells for female fertility used parabiotic (the union of two mice through an exchange of blood) mice model. This study by Eggan and colleagues tested the capacity of circulating bone marrow cells to generate ovulated oocytes and could not show any contribution of bone marrow cells to ovulated oocytes [4]. Blood or bone borne oocytes are highly debatable but bone marrow cells, at least, might have a role in enhancing women’s fertility. This might lead to the treatment of infertility. In addition, it might bring new opportunities for those dreaming of having a baby even at a late stage, but requires much additional research to be realized.

Lab & bone borne sperms

Sperm formation is known to continue throughout adulthood. It involves various steps of cellular differentiations. Maturation of sperms in the body takes more than a month in most mammals. Trials to mimic this complex process in petri dishes failed to demonstrate the production of normal, fertile sperms.

Scientists had dreamed of growing sperms in petri dishes for years. Recently, researchers in Japan developed a technique that allowed production of fertile mammalian sperms in a petri dish [5]. Attempts to make such mature sperms usually failed due to meiosis, a specific type of cell division that halves the number of chromosomes. Meiosis is very essential step for sperm cells to get ready to fuse with an egg. Ogawa and colleagues demonstrated that meiosis of sperm cells lay in a simple change to standard petri conditions. They tried various petri conditions but they ended up with a special serum free medium that is commonly used for growth of embryonic stem cells. Several weeks later, they observed formation of mature sperm cells and even half of them had flagella, a tail-like structure that sperm cells use to swim. Injection of those sperms into egg was also able to produce offspring. In addition, when they used frozen testis tissues of newborn mice, they could grow sperms as well. This discovery in reproductive biology is likely to be beneficial not only for people having infertility problems associated with sperm maturation but also children that undergo cancer therapy which destroys fertility. It is known that chemotherapy impairs fertility. Adults could freeze their sperm before such treatment, but young boys can’t. This new discovery offers such patients hope. In addition, this finding opens new avenues for protection of endangered animals that might die before reaching sexual maturity. It is a matter of time for the same technique to be applied to humans and other species.

There are also reports suggesting the generation of male germ stem cells (sperm producing cells) from bone marrow [6, 7]. Mesenchymal stem cells, which are derived from the bone marrow, have shown to differentiate into male germ cells. Studies testing the effect of retinoic acid and testicular extracts showed to induce human bone marrow stem cells to differentiate into male germ cells as shown by male germ-cell specific marker expressions. Another approach tested the possibility that bone marrow-derived stem cells would differentiate into germ cells when transplanted into the mouse testis. Using GFP positive bone marrow cells transplantations, it has been demonstrated that bone marrow-derived stem cells can also be induced to differentiate into germ cells. Interestingly, there seems to be a connection between bones and fertility.

Bones and fertility

The Qur’an tells the story of Prophet Zachariah, peace be upon him, when he secretly prayed to God to ask for a successor. He said “My Lord! My bones have grown feeble and my head glistens with gray hair from old age…” (Maryam 19:4). His prayer was accepted and the angels came with the glad tidings of his son, John. He was surprised as to how he could have a son while his wife was barren and that he had already reached infirmity in old age. It has been said by scholars that weakness of bones here refers to weakness in engaging in sex due to old age and gray hairs as a sign of infertility. It is also worthy to mention another verse where the creation of human is described as happening from a lowly fluid that gushes forth the vertebra and rib bones: Let human, then, consider from what he has been created. He has been created from some of a lowly fluid gushing forth. It proceeds (as a result of incitement) between the (lumbar zone in the) vertebra and the ribs (At-Tariq 86:5−7). As commentator Ali Unal explains, these verses refer to both the mechanism of the ejection of the seminal fluid and where it is emitted [8], which is a relatively recent discovery in biology. Remarkably, the Qur’an mentions two major bones where this fluid is emerging. Our current knowledge in medicine do not say anything about the role of ribs in reproduction or fertility but both the Islamic and Judeo-Christian traditions mention the creation of Eve from Adam’s ribs, peace be upon him. Could this refer to the relation between bones and fertility? God knows best. Lastly, it is of importance to note that one of the symptoms of menopause is the loss of bone mass. Isn’t it amazing how mysterious events regarding bones and fertility are taking place beyond our control and knowledge?

Ali Fethi Toprak is a PhD candidate at University of Texas Southwestern Medical Center.

References

1. Johnson, J., et al., Germline stem cells and follicular renewal in the postnatal mammalian ovary. Nature, 2004. 428(6979): p. 145-50.
2. Vogel, G., Reproductive biology. Controversial study finds an unexpected source of oocytes. Science, 2005. 309(5735): p. 678-9.
3. Johnson, J., et al., Oocyte generation in adult mammalian ovaries by putative germ cells in bone marrow and peripheral blood. Cell, 2005. 122(2): p. 303-15.
4. Eggan, K., et al., Ovulated oocytes in adult mice derive from non-circulating germ cells. Nature, 2006. 441(7097): p. 1109-14.
5. Sato, T., et al., In vitro production of functional sperm in cultured neonatal mouse testes. Nature, 2011. 471(7339): p. 504-7.
6. Hua, J., et al., Derivation of male germ cell-like lineage from human fetal bone marrow stem cells. Reprod Biomed Online, 2009. 19(1): p. 99-105.
7. Lue, Y., et al., Fate of bone marrow stem cells transplanted into the testis: potential implication for men with testicular failure. Am J Pathol, 2007. 170(3): p. 899-908.
8. Unal, A., The Qur’an with Annotated Interpretation in Modern English. Vol. Qur’an 86:5−7, 51;24−30 and 19:4. 2009.

The miracle of life appears in the form of a baby which develops from a fertilized ovule (zygote) following millions of other events. This series of events, which is almost always the same for every fetus, can be grouped as reproduction, differentiation, and development. The zygote completes its development in the womb; postnatal growth can continue until 20 years of age. Even though every event during the baby’s development seems to take place with chaotic reactions, harmony and order are there for us to discover. One of these astonishing events is the perfectly symmetric growth of the fetus/baby. Most organs in the human body appear in pairs and are symmetric. Babies are born with 300 bones; however, some bones later fuse with other bones, leaving only 208 bones in the adult human. It is still a mystery how long bones such as the humerus, radius, ulna, femur, and tibia are able to grow on both sides of the human body in a symmetrical manner.

Mechanisms that control growth in organs

In vertebrates, both internal developmental programs and the external factors which stimulate or inhibit growth play a role in the ultimate size of an organ. But the relative effects of these two mechanisms can vary significantly in different organs. When pieces of spleen from an embryo that is at a later stage of growth are transplanted to a newly developing embryo, each new piece grows, but not to the size of the original spleen. The total weight of all the transplanted spleen pieces is equal to a normal spleen’s weight. When the spleen reaches a certain weight, growth inhibiting factors are secreted, which stimulate negative feedback mechanisms that limit growth. When a spleen reaches a certain size, the density of the inhibiting factors increases simultaneously, halting growth. Growth in the liver is controlled by extracellular factors (various substances in the blood, hormones, vitamins, minerals, etc.). When a section is cut off of the liver, the section continues growing and developing until it reaches the size of the original liver. The thymus has a growth process that is executed by a cellular genetic program. When sections of a thymus taken from the embryonic period are injected into developing mouse embryos, every section grows until it reaches the ultimate size.

More evidence of cellular growth programs was acquired via an experiment that was carried out with the salamander genus Ambystoma. When the leg bud of the larger species was injected into the smaller species, it would at first grow slowly, but then it would reach the normal size of its own species (the larger species).

Distinguishing growth and symmetry from one another

Both the arms and legs have long bones. A long bone consists of two parts (diaphysis and epiphysis). The diaphysis is the middle (core) part of the long bone. It consists of hard bone tissue, and is like a tube. The hyaline cartilage-covered joint forms the epiphysis of the long bone. In a growing bone, there is a growth plate (epiphysis plaque) made of hyaline cartilage; this is located between the diaphysis and the epiphysis. The epiphysis plaque causes the bone to grow longer; when growth is complete, the epiphysis plaque ossifies (becomes bone). In other words, growth stops. There are some clues that show the existence of positive feedback mechanisms which control the symmetric and balanced development of the arms and legs while the fetus is still growing. The arms and legs grow due to the development and growth of the plaques located at opposite ends of the long bone. The ultimate size of the arms and legs are proportional to the size of the finger bones (phalanx) and the metacarpus. According to current knowledge, growth in our arms and legs is only controlled by internal growth programs and the active growth of the plaques. We do not yet know the mechanism through which how much the bone must grow and symmetrically with the organ (the other arm or leg) on the other side of the body. But even if this is discovered in the future, we will continue to appreciate the perfect and miraculous aspect of this phenomenon.

In addition, in growth-plaque transplant experiments, the development of the transplanted growth plaque is dependent only on the age and size of the donor. Growth plaques cause the bone to grow, but the plaques themselves remain the same size for years. The cartilage cells they produce (chondrocytes) exchange places with the bone cells (osteocytes) in harmony and without destroying the length of the bone. Cells from different areas of the growth plaque act differently. Stem cells are found on the upper section, near the epiphysis. Immediately above them is an area where cells reproduce very quickly. At the bottom of the epiphysis, the cartilage cells grow up to 4 to 10 times larger than their normal size (hypertrophy). Cell reproduction here is mostly due to hypertrophic chondrocytes. The chondrocytes die and break up, then change places with the bone tissue. The dynamic process of these events in the growth plaque repels it from the bone area, and as a result, the bone grows longer.

Sustained symmetry despite cell sequence and speed of reproduction

The rapid growth rate in the legs and arms during the embryonic period continues to increase until the child is three years of age. This growth rate slows down until the individual reaches adolescence. During the fastest growth period, which is from adolescence to the early 20s, the growth rate rapidly increases. For example, most people who grow between 30 and 37.5 cm during the first two years of life can grow between another 7.5 and 10 cm every year during adolescence. At the onset of adolescence, rapid growth due to a sudden change in the volume of cells is observed. After adolescence a sudden falling off in the speed of growth can be observed due to the effect of hormones on the growth plaques in the spine and other long bones. The growth plaque now fuses with the neighboring cells and growth stops. However, the fusing of the growth plaque is the result of the cessation of growth, not the cause. After growth stops, the growth plaques begin to disappear. When the reproduction potential of the cartilage cells in the growth plaque has been exhausted, the growth plaque begins to disappear.

Growth plaques in different bones can trigger growth at various rates; these rates can differ as much as seven times. In fact, growth plaques on different ends of a bone can have different growth rates, provided that this rate is consistent with the genetic program. The number of cells on the growth line is 40 times more than in other areas. The number of cells produced here can exceed 10,000 cells per day. For symmetric growth between the arms and legs to be sustained, the number of cells in the growth plaque must be the same or very close. Experiments carried out on rats show that eight cartilage cells leave the growth plaque to exchange places with cells above them every day. It can be said that the growth of the bone is caused by the increase of cells in the growth plaque (which sustains its size). The growth rate caused by the growth plaque can be calculated by multiplying the growth plaque’s cell production rate by the average length of all of its cells. Different growth plaques provide different growth rates. This difference can be caused by the difference in the size of the growth plaques, the difference in cell production rates, and/or the difference in the hypertrophy (growth) rate of every cell. The upper growth plaque in the tibia of mice generates 16,400 cells every day; the average life span of these cells is around 30 hours. Can such harmonious, symmetric, and equivalent growth in the arms and legs-despite the large number and variety of cells-be the work of pure coincidence, mindless nature, or unconscious molecules?

Do hormones play a role?

The main molecular players that organize longitudinal growth in bones during childhood are the growth hormone, the thyroid hormone, and corticoids. The sex hormones (androgens and estrogens) are programmed to influence growth during adolescence. Estrogen is the main determiner of characteristics related to increased height and an increase in bone quality, as well as adolescent-related physiology. These hormones are in charge of coordinating growth throughout the body. It is for this reason for women, after the menopause, the production in estrogen decreases and osteoporosis and brittle bones can occur. According to the current view, cartilage cells have a certain genetic reproduction potential, and when this potential finishes, growth stops. The growth rate during the embryonic period is 20 times higher than that of mid-childhood. The growth rate drops greatly during mid-childhood. If we exclude the noticeable increase during adolescence, the cells responsible for growth have begun to age. The bones on opposite sides of the body stay about the same size, despite all of these changes in growth rates. Circulating hormones and neuroendocrinal factors are believed to play important roles in maintaining symmetric growth. But there is no conclusive evidence to support this belief. Even though one can think of factors such as pressure, tension, and sports as helping control harmonious and symmetric growth of bones, no proof has been attained from controlled experiments. As a person ages, a gradual decrease in growth can be observed. Even if a growth plaque is placed into another organism, be it young or old, the growth rate of the bone does not change. This shows that symmetric growth in long bones is controlled by a program that is operated by internal factors, which is also compatible with the genetic program. When chemical-based medication is given to postpone growth, after the medication has been eliminated, the growth plaques grow faster for a short period to compensate for the lost time. These findings show that timing and the location and circumstances of the cell are critical parameters for reproduction. If the cartilage stem cells in the growth plaque have a certain reproduction potential, then it is clear that cartilage cell reproduction stops when growth comes to an end. If growth inhibiting factors slowly accumulate in the growth plaque, this might cause a deceleration of growth over time. Another possibility is some sort of “meter” in the unconscious and mindless stem cells, which keeps track of the number of cell divisions and thus controls aging. The estrogen in our body has a duty of closing down the growth plaques and speeding up the aging of cells. However, we should not forget that estrogen plays the special role of closing down all of the growth plaques at the same time. Estrogen is one of the visible causes of fertility, growth and development, and resilience. Estrogen also represents femininity and fertility at all levels.

When the signals from unconscious cells in the growth plaques and the quite sophisticated interactions among all the factors that influence growth, all of which require an all-encompassing knowledge to be executed, are taken into account, the impeccable genetic programs of different growth plaques on the two sides of the body that leads to the formation of the arms and legs, as if they have been molded in a factory, is absolutely amazing for anyone who reflects upon it.

References

• Wolpert L. (2010).”Unsolved Mystery: Arms and the Man: The Problem of Symmetric Growth.” PLoS Biology. 2010 Vol. 8(9). pp 1-3
• Extremity Development during the Embryonic Period (www.visembryo.com)

White blood cells (leukocytes) are fewer in number and their duty is to fight against germs. How this process works is to be expounded by the immune system under a separate title. The red blood cells are my main building blocks and they are born by the dividing of the main cells in the bone marrow. After passing through a few phases, they lose their nucleus and are filled instead with hemoglobin, a magnificent substance containing iron. Hemoglobin’s most vital function is its binding oxygen and then carbon dioxide after releasing it. Hemoglobin reaches everywhere, traveling with the blood stream. When it comes to the lungs, hemoglobin dumps the carbon dioxide and replaces is with oxygen. Then it supplies this oxygen to the cells and removes the carbon dioxide, which is produced by burning organic compounds. So its short life passes with the same ceaseless cycle to continue your life. Hemoglobin molecules’ longevity is approximately 120 days. They contain no cell elements like ribosome, mitochondria, and nucleus and therefore cannot repair themselves. They simply die when they get old. Sad? Not at all! Red blood cells fulfill the duty they were created for and leave the stage for new ones. They are broken down in the liver and bone marrow and the iron they contain is absorbed. A certain part is transformed into bilirubin, giving bile its yellow color. As you see, nothing is truly wasted.

The red blood cells in circulation number around 25 trillion, and this number does not vary greatly, as the dying ones are constantly replaced. Their measuring gives doctors an idea about possible diseases. The amount depends on various factors’ reciprocal balance. A hormone (erythropoietin) secreted by the kidneys increases the rate of production of red blood cells, in response to falling levels of oxygen in the tissues. If you lose blood due to an accident or medical operation, the stem cells in the bone marrow receive an emergency alert to produce more red blood cells. On the other hand, if you get a blood transfer, stem cells are ordered to stop producing, due to the excess of red blood cells. You see, even such basic knowledge about bodily systems fills the learner with wonder.

Deficiency of red blood cells, scientifically known as anemia, should not be ignored. It results in pallor and weariness; you feel like sleeping more. In order to avoid this condition, your body needs different things such as group B vitamins (B6, B11, B12), vitamin C, amino acids, and iron. Since it is hard to pinpoint the deficient substance, doctors generally prescribe iron-rich multivitamin supplements.

Red blood cells divide into four types, which determine the blood groups A, B, 0, and AB. In addition to the blood group, another feature known as Rh (rhesus) factor is important to know particularly before a blood transfer. Transferring the wrong type of blood may result in death.

Platelets, which are scale-shaped cells and circulate with me are not independent; they are pieces which came off bigger cells. In a cubic millimeter of blood, 250 to 350 thousand of these little scales are found and their duty is of vital importance. If it weren’t for these pieces, the slightest cut could cause death because your bleeding would not stop. Clotting is a great blessing. It usually blocks the surface of a wound within five minutes, stopping the flow of blood and saving your life. Clotting is realized through particular molecules in these minute scales as a result of a complex chain of reactions using enzymes, vitamins, and salts. Every step of this chain of reactions is another stitch to fix the wound. Other blood cells pile up and stick together behind this net and they dry up. If such clotting occurred inside the blood vessels, it would make a disastrous effect by blocking the bloodstream. I also have enzymes to break down little amounts of such clotting. As you see, everything is splendidly organized.

Peter! A blood test reveals very critical medical data. As I visit every organ, I exchange certain substances with them. Therefore, detection of an unusual substance in me can be an early warning for a disease. Nowadays, it even helps an early diagnosis of cancer.

It is not so easy for me to explain the wisdom behind all of my duties and capabilities. But to give you an idea, there are specialized departments for studying just me at medical faculties and research institutions throughout the world.

We agreed with the other organs to explain the splendid art inherent in us to you; we have patiently waited our turn. Our aim is to remind you to look after yourself so you will continue to live a healthy life and consciously perform your duty of servitude to our Lord Who created us. In addition to your perfections, as human beings you also have certain faults, such as being negligent, deceptive, or forgetting easily. Even if you realize that these are your faults, each bears a distinct wisdom in terms of Creation. If from time to time you can succeed in avoiding this negligence and escaping these experiences by using these shortcomings as a springboard or platform from which to depart, you will be able to reflect and contemplate on the attributes of God with greater admiration.

Indeed, we are just inside the gateway of the body that opens to the outer world, the mouth, an area through which the various substances you eat to stay alive pass through the mechanic process we implement before actually entering the body.

When food first enters the mouth, it is passed through a grinding process that carries out a mechanical breakdown before the chemical breakdown in the stomach and intestines. We teeth are aligned along on your lower and upper jawbone. When you were only a two-month old fetus, the Creator Who is aware of the importance of our tasks began to prepare us, and we were planted, just like a seed sown in the earth, in the crevices in your jawbone, and concealed by your gums. But still, we do not appear immediately after birth, because we may hurt your mother when she is nursing you. Initially, it is necessary for you to be fed with that unique nourishment, your mother’s milk. However, we begin to gradually emerge in the form of tiny stumps while you are still being nursed by your mother, when you are around six or seven months old.

We were created to cut, chew, and grind food of various textures and hardness. The number and mechanical functions of my colleagues, who have names such as incisors (cutting teeth), canines, premolars, and molars vary. The incisors, which are at the front, begin to appear when you are still only 6–8 months old, the ones immediately beside them erupt when you are 8–12 months, the premolars appear when you are 12–16 months, the canines at 16–20 months and second premolars when you are between 20–24 months old.

During this period, we are known as the milk teeth. When you are 6–7 years old, the molars emerge and then when you are 7–8 years old the central incisors appear; between 8 and 9 years of age the lateral incisors, between 9 and 11 the first premolars, between 11 and 13 years the second premolars and the canines, and finally between 12 and 14 years of age the second molars erupt; the third molars, known as the wisdom teeth, usually appear any time between the ages of 17 and 40, although sometimes they do not come through at all. The two front incisors, the canine beside them, and the two premolars and three molars, that is, a total of eight teeth, constitute half of the jaw, but all the teeth work as a team of 32. Sometimes you may hear about humans who perform various experiments regarding our strength. My strongest chewing force was recorded as 1900 Newton. In a demonstration of strength, a human was capable of lifting a weight of 620 lb as high as 7 inches from the ground. Although each of us has different functions and appearances, in terms of where we are situated, in general our anatomic structures are the same. The enamel layer covering me is very hard and shiny. My enamel layer is even stronger than bone. My sections, which cut hard substances you put in your mouths like knives without bending, are in fact covered in enamel. Beneath the enamel surface is a solid, bone-like substance known as dentin, which has a slightly different composition than that of the bone found in other parts of the body. The space in the center of this layer (known as pulp chamber) is filled with blood cells and nerves that nourish me. The section of each of us that is buried beneath the jaw bone is called the root, while the part that is visible and which you brush daily is called the crown. Throughout your lives, everything you put in your mouths, whether it is hard, soft, corrosive or acidic, comes into contact with the crown. Some substances can damage us. Even stone or steel would not be able to withstand the conditions that we teeth are exposed to. Although made of metal, a carpenter’s saw becomes blunt, and even a blacksmith’s grinder looses it effect after a while. But if you take good care of us, we will serve you throughout your entire life. Unfortunately, I have noticed that you do not take care of us at all. You eat sweet things, but you do not clean us, you eat meat, but you do not brush us, you relentlessly use us to crack open nuts, and pour anything you find, whether hot or cold, over us. We can withstand this for now because we are still young, but it is impossible to say how long we can carry on like this. If any of us cracks and bacteria begins to eat away at us, eventually causing us to decay, you will start to complain, but it will be too late.

The Prophet Muhammad, peace be upon him, gave utmost importance to us in his daily life. Whenever the opportunity arose, after eating, before prayer, in the morning when he woke up, the Prophet constantly used a miswak, a cleaning twig, and cleansed us with affection. This is why we sparkled like pearls when he opened his mouth or smiled, and those close to him never sensed an offensive odor from his breath. But many people today do have bad breath because they neglect us. Not only does the smell of bad breath make others uncomfortable, but you are also causing harm to yourselves. After the bacteria that hides in the crevices on and between us makes a hole through the enamel and the bone beneath it, this bacteria then begins to spread to your entire body through the blood cells in the pulp chamber, causing damage to other organs of your body. These bacteria can damage vital organs, such as the heart or the kidneys. At first, you do not notice this, because this occurs over a long period. But these bacteria can gradually destroy many of your organs. When you do finally realize what has happened, it could be too late; your cardiac valves may have stopped working properly, or the filtering function of your kidneys may begin to fail.

If you begin to lose us one by one, initially you will notice the change in the taste of your food, then defects in your speech, and eventually you will notice facial deformities and sunken cheeks. You will have to make dentures at great expense, and only in this way will you be able to restore your appearance; but in terms of function, you will never be able to substitute us with those artificial dentures!

You know that one of the main characteristics that distinguish us from animals is speech. Although the focal point of speech is in the brain, speech actually emerges as a sound or words with the collective assistance of many other organs. These are mainly the lungs, the larynx (voice box), the ears and the tongue; but we too play a big role in the correct pronunciation of many letters and words.

In addition, the mechanoreceptors in us and the cell network in our roots display such perfect precision that when we chew, we do not bite your tongue or cheek. Therefore, you can adjust the force of biting pressure for substances of various textures. If these receptors and cell network did not exist, you would use an identical chewing strategy for eating substances as hard as an apple or as soft as pudding. In which case you could not bite an apple or you would attempt to eat pudding with excessive pressure, causing us to grind together with unnecessary force, even breaking us.

So you can see that nothing has been created without a purpose. Are there any unnecessary details in creation? Of course not! This is impossible; as the eternal wisdom and power of He who created us would never permit something which is deficient or of no purpose..!

Dear Peter! I think this should be sufficient in describing ourselves to you. Naturally, the food we breakdown is not in a condition to be swallowed immediately. Therefore, our neighbors, the salivary glands can explain what happens next…

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

It was.

Brittany’s path towards recovery had been abruptly cut short. After three months of chemotherapy, radiation, and alternative treatments that never ended, and with a bone marrow transplant on the horizon, Brittany had unexpectedly developed a massive infection that could not be controlled. She had been doing so well, and no one saw it coming. I was told that she had passed away in the early morning hours while I was still sound asleep in my warm, soft bed. My mom was on the phone when I arrived in the office. She was equally devastated not only because Brittany was my dear friend, but because she was also the niece of her best friend. It was a close inner circle. Now someone was missing from it.

As I reflect on that horrific day over four years later, I have finally come to peace with Brittany’s tragic and untimely death, though I doubt I will truly ever understand it. Yet I have realized that we have no choice other than to come to terms with death because it is an integral part of the life process. However, I do not consider Brittany to be truly gone. I believe she lives on in so many ways, and I think that we as a society are just on the threshold of understanding life beyond death and the spiritual continuance and connection that lives on in the day to day lives of everyone who knew the deceased.

In the most simplistic terms, I see Brittany in the spirits, faces, and actions of every person’s life she ever touched. I see her in her mother and how she compassionately and gently treats other people; I see her in her sister and her never ending kindness and understanding; I see her in her aunt and her eternal optimism; I see her in the many friends she had who worked so hard to keep her memory alive within a very large high school environment; and I see her in myself when I try to embrace her passion, patience, and inner peace. She lives on in all of us and always will. I have come to believe that a person’s spirit and soul are truly separate from their earthly body; I’ll never see her smiling face again other than in pictures, but I still see her every day.

During Brittany’s brief but valiant battle with cancer, she embodied so many traits to which the rest of us can only hope to aspire. She exemplified a true sense of inner grace that I had never witnessed before in any other person. Throughout her illness, she never showed any outward signs of fear, although undoubtedly she was terribly frightened. She never complained although she must have often been in excruciating pain. She was always positive and optimistic and tried to keep a smile on her face, even though I know it must have been an incredible challenge. I knew she was struggling, but she didn’t want anyone to know. She never wanted to burden anyone, even though she was facing the biggest battle anyone can ultimately face. Brittany did not have the benefit of growing old and wise, yet her spirit is endless and inspirational. At only fifteen years old, she never even had the opportunity to graduate from high school, go to college, fall in love, raise children, and live a long life.

She was only in the 9th grade, a mere freshman in high school. So what does this say about a teenager who is selfless enough to not want to impose any pain on anyone around her when she was clearly suffering? I often wonder if she thought that she might die, even though she always said that she was going to be okay, and even proclaimed that she planned to run laps around the hospital once she was finally released. Certainly, she thought of others more than herself during this very difficult time. I sometimes wish I had talked to her about death just to know more about her thoughts on the subject; I just don’t think that she ever considered death to be an option, but I’ll never know for sure.

Yet even today I continue to feel Brittany around me, just as I see her in the all people’s lives that she forever touched. She has obviously left her earthly body, but that does not mean she is not present in the lives of those who loved and continue to love her. She had such an incredibly strong spirit and it was not in any way defined by the body that she so briefly resided in; her spirit remains while it has also moved on to its next destination, no doubt to find a higher purpose. She will never truly be gone, nor will the people who knew her and loved her ever let go of what she represented and the joy she brought to their lives.

What ultimately defines a person’s spiritual being both in life and in the afterlife? Is the earthly body and spirit a completely different entity from the heavenly spirit or does it represent an ongoing continuum? Does a person’s spirit die just as the body dies? I contend that it does not because the spirit is never something you can reach out and touch. It is real, but it is not palpable, even in life. You can’t see it, touch it, taste it, hear it, or physically feel it, yet you can sense it. A person’s spirit forever defines their goodness or lack thereof in some circumstances, their impact on other people’s lives, and the innate individual qualities that make that soul unique.

A person’s spirit is not finite by any means, but rather it is all encompassing. It is the inherent essence of the soul of an individual, whether living or deceased. Could anyone truly claim that the spirit of Martin Luther King Jr. is dead and gone after his inspirational, albeit abbreviated life and his infamous words, “I have a Dream”? Conversely, doesn’t the spirit of Adolph Hitler similarly still exist in the families that continue to mourn the atrocities endured by the victims of the Holocaust? A spirit is not limited by life or by death, by good or by evil, nor by a moment in time or by eternity.

In life, Brittany was indeed unique and someone many would consider to be a refreshing and optimistic soul, and certainly she continues to be the same years after her passing. No one ever had a negative thing to say about Brittany, even in an often catty high school environment. She was never among what many would consider the “popular” crowd; rather, she hung with members of the Anime Club. She was generally happier reading a book than going to the latest movie. She was quiet and introspective, scientific and analytical, not one interested in parties, dating and high school football games. Wherever she is today, I envision her working with the angels, perhaps on mathematical and scientific innovations that may eventually benefit those of us on earth. She certainly wouldn’t be happy sitting idle. She would always need a challenge and an opportunity to use her amazing brain power. God must have needed her for a much higher purpose.

Surely her untimely death has left her family devastated and questioning why this happened, especially to such a kind and innocent young person. For those of us who knew and loved her, it obviously makes no sense, and I continue to question, but in the end, know that I will someday understand. But I know for a fact that she wouldn’t want sadness or bitterness. That’s not at all what Brittany was about. I believe that she would instead hope that we look inside of ourselves and take a harder look at what purpose we want to fulfill within our own lifetimes.

Life is inherently limited. We all know that someday it will come to an end for each and every one of us. It is very, very sad when it comes to an end prematurely; at least by our standards. But God’s standards may be infinitely different from our own, and in the end, an individual’s legacy to those left behind on this earth cannot be measured by longevity. Further, it does not matter whether a person is a John F. Kennedy, an Albert Einstein, a Mother Teresa or a small town high school student, because it is not the number of lives we are able to touch, but the spirit in which we are able to do it. As long as a life is lived with a sense of true, unabashed passion, the spirit as we know it can never be extinguished in the minds of those left behind. More importantly, for reasons yet to be understood by mere mortals, that spirit has found another place in time, another purpose to fulfill, inevitably choreographed by the most divine power.

When I graduated from high school in 2008, Brittany’s mother gave me a memorable gift. Knowing my love of music and dance, she presented me with a CD by Lee Ann Womack with the feature track being “I Hope You Dance”. The lyrics are inspirational and timeless. In part, they are as follows:

“I hope you never lose your sense of wonder,
You get your fill to eat but always keep that hunger,
May you never take one single breath for granted,
God forbid love ever leave you empty handed,
I hope you still feel small when you stand beside the ocean,
Whenever one door closes I hope one more opens,
Promise me that you’ll give faith a fighting chance,
and when you get the choice to sit it out or dance –
I hope you dance, I hope you dance.” (MCA Nashville, 2000)

Brittany’s mom, whose daughter should have been in that same procession marching in cap and gown to “Pomp and Circumstance”, receiving her well earned diploma, simply wrote the message, “April, I hope you dance!” At that moment, I once again felt Brittany’s eternal presence.

There is without a doubt a higher plan, in my opinion, for every relationship we encounter on this earth. Brittany and I will see each other again someday, and I have no doubt that she will still have that beautiful, inspirational smile on her face. Still I miss her, but I do know that she is not far away. And when we do meet again, she’ll probably just say something like, “Hey there, April, I missed you, but I told you I was just fine.”

Since that terrible day in 2005 when I found out that my best friend, who was thought to be on the road to recovery, suddenly and unexpectedly lost her battle, I have done a great deal of soul searching and introspection. Sometimes I wonder how the potential and very unselfish bone marrow donor in New Jersey felt when he heard that he matched a young high school girl thousands of miles away and could save the life of this anonymous recipient. I imagine that he must have been excited yet somewhat nervous because the bone marrow extraction from the donor is said to be somewhat uncomfortable. But then I wonder how this man felt when the statistically unlikely match failed to come to fruition. I would think that this stranger must have grieved as well, or at least this is what I want to believe.

Brittany and this unknown New Jersey resident had more than bone marrow in common. Having known and loved Brittany, I knew she was kind, loving, unselfish, and generous. Even though I never knew her potential donor, he obviously embodied the same qualities. And when I say “embodied,” I mean it in a spiritual sense. If Brittany had not suffered a massive infection, a person who had never met her was willing to undergo an invasive procedure in an attempt to save her life. That is a person’s true spirit. It is what defines us, it is who we are in life and thereafter, it is the life we live while we are here on this earth and legacy we ultimately leave behind.

April Bollig is pursuing a degree in Elementary Education at University of Colorado at Colorado Springs.

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.

Some people might see me as a rough piece of flesh that wiggles in the mouth. Of course I am not that simple! By looking at my color, some experienced doctors can even diagnose an illness. For example, some well-known symptoms that I show are whitening due to fever, becoming dark brown when you have typhoid, blackening because of a yeast infection, or having a smooth surface because of anemia or lack of niacin (a B-group vitamin).

If you are wondering what my primary duties are, I can say that the first is to help to produce speech, an ability which distinguishes you human beings from animals. For sure this speech production is not only mine. First of all the brain, which is the coordinator of all the organs including me, regulates all my movements in speaking. The other organs that help me form sounds to make words are your teeth, lips, palate, the vocal cords in your throat, and your lungs, which work like an air pump and vibrate those cords. As you see, so many of us work together just to produce your speech.

Other than the speech function, my second major duty is to work as an inspector to taste and process the countless fruits and delicious foods that are given by God. That is how you get an idea about an animal- or plant-based substance that you want to eat. If I did not exist, you might die because of a poisonous plant that you ate out of hunger. Many poisonous substances have a bitter taste. Indeed, I can sense their bad taste the moment I touch them and warn you to spit out the thing in your mouth immediately. When you eat sweet and delicious things, however, I make you remember and thank God, who has given them to you. However, you should be careful about my fondness for taste and control yourself since that is part of a God-given test. My Creator has made a relation between my love of taste and the evil-commanding side of your soul. He has also made me a step for your spiritual development. If you eat and drink too much, which means you are misled by your evil-commanding side and abuse my sense of taste, it will be you who lose. I do what my duty requires and get the taste of everything. But it is your job to use your will power and not to be defeated by your evil-commanding self (nafs). I will never stop you, whether you eat one piece of baklava or ten; I will get the taste of every piece. Do not ever blame me for that!

I have another function that many people are not aware of. My movement causes a negative pressure in the cavity of the mouth. Are you wondering what this negative pressure does? This pressure is needed especially for babies to nurse on their mothers’ breast easily; I help them in the sucking movement. In addition to that, as everybody knows, I have very important functions in chewing and swallowing food. I manipulate the food in your mouth; I soften and moisten it with saliva so that it can be easily swallowed. Also, during swallowing, I move the food back toward the pharynx. I have to be very careful while doing all this, since at my smallest mistake, your teeth might bite and hurt me.

Of course, I can do all this only with the help of my Creator, who has built my anatomy of delicate tissues and cells. Since He never does anything absurd or useless, He has given every organ qualities that are both esthetic and functional. My main body consists of seventeen muscles, eight of which are in pairs. They extend in all directions. Among those muscles are the lipid membrane and some salivary glands. I am the most flexible organ in your body. My many strong muscles enable me to move in lots of directions easily. Those muscles are covered by an epithelial lining which is called the mucous membrane. The small projections on my upper surface are called papillae. These papillae are of several types. They contain receptors which allow you to sense taste and the salivary glands that help me stay wet all the time. The papillae cover as far as an A-shaped line towards my back which makes up a third of my length. Here at my back, there are plenty of salivary glands and the lymphoid tissue, also known as the lingual tonsil. Many germs that enter through your mouth get trapped here. The papillae are named according to their shapes. The filiform papillae (which are long and thin) do not contain taste buds. They only provide a rough surface to move the food easily. The food is moistened by your saliva and crushed by your teeth. Then, with the help of these papillae, I help to shape the food into smaller pieces to make it easier to swallow. The fungiform papillae are mushroom-shaped and scattered among the filiform papillae. They are located at the center of my top surface and they contain taste buds. The circumvallate papillae lie along the A-shaped line which makes up the border of my back. These papillae are larger in size and smaller in number; there are around thirteen of them. Each taste bud on the fungiform papillae has 50 to 75 receptor cells which live for only seven to ten days. When cells die because of hot or acidic foods, new ones are created to make new nerves for the taste buds. Only substances that are dissolved in water can reach the taste receptors. That is why I cannot taste a dry substance that you have taken into your mouth right away; it has to be moistened and softened first. Tasting occurs in the receptor cells of taste, where some analyses are undertaken much more delicately than in a chemistry laboratory. My receptor cells change this chemical stimulus into an electrical stimulus and send it to your brain. This electrical stimulus allows the sense of taste to be perceived.

Among the many kinds of taste, there are four major groups. The taste buds for sweetness are located near my front; the taste buds for saltiness are scattered widely on my surface; the taste buds for bitterness are found at my back; and the taste buds for sourness are on my sides.

My under surface extends between my tip and the floor of your mouth. The mucous membrane that covers this surface is smooth and does not contain papillae. It is purple in color because of the many blood vessels that are inside me and nourish me. By the way, the famous saying that “the tongue does not have a bone” is wrong, since I do have a bone. However, this bone is not located in my front body, which is why I am very flexible and I can say whatever you command me to say. But by my muscles and ligaments I am firmly bound to a U-shaped bone (the hyoid bone) at my root. I am connected to your lower jaw by this bone.

I can have disorders, like every other organ. In fact, many disorders in me are an indication of disorders in the other organs or of a metabolic illness. For example, mouth ulcers can often be seen on me. Some types of mouth ulcer are caused by stress, lack of sleep, or lack of vitamins. Others occur as a result of absorption disorders and as a symptom of Behcet’s syndrome. Some ulcers can last for weeks and they can be very painful. You might suffer from this pain especially when you speak and eat. Diseases such as syphilis and herpes also show themselves as ulcers on me. I might even become cancerous in people who smoke or in those who eat and drink things that are too hot. I sometimes show the symptoms of some metabolic disorders like Down’s Syndrome, the blockage of lymph vessels, glycogenosis and amiloidosis. In these disorders, my muscle mass shows excessive growth due to abnormally deposited glycogen and amyloid.

Dear Peter, until now, your “speechless organs” have talked about themselves in their own tongue. I have always talked, but I have always talked on your behalf, expressing your thoughts and feelings. It is you who are responsible for what I have said, good or bad, since I am bound to your will power. However, today I spoke in my own tongue, and on behalf of our Creator. As is well known, I am an organ that has great potential for both evil and good. It is your duty to control me and use me well. Do not ever forget that I am not a simple mass of muscle, epithelium and nerves. Rather, I am a tool that can be used for both debasing and elevating you. From now on, when you eat an apple, do not swallow it before chewing well; wait till I get the flavor of it very well. In that way, you will have an opportunity to thank God for the food you are given. He is the One who not only gave you that apple, but also me, the organ that can taste it. This is just another amazing thing that makes your life beautiful! By thanking God, you will deepen your worship of Him.

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

I have been positioned in the center of your face so masterfully and delicately that even my slightest displacement would cause your face to become disfigured immediately. You would lose your good looks if I were wounded or spoiled. It seems to me that after creating your whole face and body, God placed me very accurately so that I can be in perfect harmony with them, and even with your soul. We noses appear in countless shapes-slender, long, narrow, wide, flat, Roman (convex), sharp and stubby noses. In the past, some wise men used to comment on people’s personality by looking at the posture and shape of their faces and bodies. The different shapes of noses would give them ideas about the intelligence and the will power of each person. It is true that there is a relationship between my shape and your personality. However, it would be wrong for someone to claim to know all about you just by looking at my shape, since your other organs affect one another too; some can neutralize the effects of others. Moreover, discipline and education can change many of the characteristics of a person. So, do not judge people just by looking at their nose.

Anyway, since these are subjective matters, they are not our focus now. What I would like to tell you about is the objective truth about the delicate art and meaning in my creation. My Creator has designed me as a projecting organ on the head-and not only on your face, but also all vertebrate animals, especially mammals. I am the organ that is used most by animals to hunt for food, to feed, and to look for their young or their mate. I am placed at the front of your body, and like a detector I sensitively recognize smells. When animals find something new, they first poke me into it to understand what it is. That is why the idiom “to poke your nose into something” is used commonly among humans, meaning to interfere with something that does not concern one. Most animals use the sense of smell more than humans do. Since they do not possess the intelligence and consciousness of humans, they acquire some of the necessary knowledge to survive through their sense of smell. However, humans are given intelligence and consciousness, and so they are not supposed to “poke their nose” into everything. Of course, that does not mean that I am useless. On the contrary, I have many functions and a complex and meaningful structure.

In the middle of your face is my external component, which is shaped like a pyramid. Because it is made of cartilage, this part is quite flexible. My tip is beaked and there are plates on my two sides. The cartilage in my tip is connected to a bone in my upper part between your eye sockets. This bone, called the nasal bone, is a part of the main bone of the forehead. A cartilaginous bridge that is lined in the middle divides my nasal cavity into two nostrils which lead to the outside. The hard palate at my base also makes up the roof of your mouth. The soft palate that is behind this extends to the nasal portion of the throat (nasopharynx). During the act of swallowing, it rises and closes off the upper pharynx to prevent food and saliva from escaping from your throat and being forced up into my back. If, when eating, you feel tickling in your throat and cough, this palate cannot close off, and the food can lodge in me and come out of my nostrils. Another benefit of this system can be seen in patients and those who are about to have surgery, when their pharynx is closed off. In such situations, patients are provided with food, liquids and air via a tube which runs through me.

The journey of the air you breathe, which you have to do in order to survive, starts with me and continues as far as your lungs. The air that enters through my nostrils is not always clean and of good enough quality to enter your lungs. If low-quality air reaches your lungs, you will get cold, infected, and sick. To protect you from that, our All-knowing God created everything carefully, taking measures to ensure your well being. He has placed air-filtering hairs at the front part of my cavity, and He has covered the inner surface of my rear with a mucous membrane (mucosa) that has a fluid form. The structure of my cavity is quite complex. Along with my two lateral walls, there are three horizontal bone shelves called the concha (or the turbinate), comprising the inferior, the middle and the superior turbinates. These narrow, shell-like structures increase the surface area of my cavity and thus help to warm and humidify the air easily before it reaches the lungs. That is, the air you inhale does not pass to your lungs until it is conditioned and filtered by me. This process is initiated by the hair in my front part, which prevents the entry of dust particles. Then, the air passes through the curled aperture formed by the concha. The concha is covered by a sticky mucous membrane which produces a secretion. This slippery secretion, along with the cilia, traps smaller foreign particles such as the dust of coal, soot, bacteria or pollen. In addition to that, since the pressure inside me is lower than the pressure outside, I can easily warm and humidify the air that passes through me.

The sides and the surface of my superior concha are lined with a very special epithelium which has a role in the sense of smell. The smell receptors, which are the cilia cells, and other supporting cells constitute the olfactory epithelium for smell. Everything that releases molecules into the air has a smell of its own. Perception of a smell occurs in the brain as a result of a very complex chain of reactions. Indeed, I have no idea about how this process happens but people talk about several theories. Since the vibration and the structure of every molecule which reaches me through the air currents differ from every other, each molecule causes different chemical reactions and electrical impulses. The molecules that come through the air dissolve in the moisture which lies on my epithelium and they chemically stimulate the cells for smell. If my mucosa dries out and loses all its moisture in dry air, it becomes more difficult for the molecules to dissolve and for you to breathe. My sense of smell also weakens or gets lost in the event of a lack of the element of zinc, which normally exists in small amounts in your body.

There is a reason why the color, taste and smell of garlic are different than that of a rose or jasmine flower: it is because each creature is created out of different compounds, as if in a laboratory of its own. Therefore, the molecules that spread into the air from those different compounds and the impact they cause will naturally be different. Indeed, what is interesting here is the wonderful system which perceives each of the molecules of so many different compositions as a different smell, categorizes it, and stores its information in memory. Whenever I experience a new smell, by its composition and vibrations, I instantly figure out its difference from other smells. Then, I help to store it in the brain’s memory related to the smell so that I can recognize that smell if I come across it again. All of those functions in their complexity remain an enigma which is still being studied by physiologists of smell. Another wonderful attribute of my smell-receptor cells is the fact that they sense the smell very strongly at first and after a while, they are not as strongly stimulated as before, resulting in a temporary paralysis of those cells. Thus, a situation called “habituation” occurs, and this is an indication of God’s mercy. If God had not created this “fading” of constantly existing smells, the sewage, garbage, tannery or butchery workers would not be able to do their work.

The mucosa that lines my cavity can easily become swollen with blood and tissue liquids. During viral or bacterial infection, or an allergy like hay fever, my cavity might become blocked completely, which makes it hard for you to breathe. Infection of your upper respiratory tract causes me to run and get blocked. You know how stagnant water gets smelly and swampy, whereas running water does not hold dirt. Similarly, when I get blocked, bacteria reproduce very fast and get transmitted to other respiratory organs. That is why, when you catch cold, you must do your best to prevent my getting blocked. Hot, aromatic or spiced teas might help you, but the best thing is to pour a weak solution of saline (salt water) into your nostrils, which will clear the congestion. As for nasal drops, do not use them unless you have to, since they will cause addiction and other side effects.

Your skull also contains four major pairs of air-filled cavities (sinuses) at my sides behind your cheeks and above me behind the forehead. In the event of infection of your sinuses, inflammation of your tonsils, or the growth of polyps, my discharge becomes constant and turns into flu or chronic rhinitis. Besides that, if I bleed it may be an important first symptom of many illnesses. Many conditions, including high blood pressure and several illnesses with fever cause bleeding inside me. Indeed, bleeding from me in patients with high blood pressure can be seen as a warning and protection against serious conditions. If, because of high blood pressure, my blood vessel did not split, bleed and decrease the pressure, a vessel in your brain would split, which would result in a much worse scenario.

Peter, from now on, do not ever forget to give thanks to God when you smell a flower or anything else with a beautiful scent. Inhale the air deeply with the pleasant impression the scent leaves on your soul. Our Lord God Almighty, who has given you the air as a blessing, bestowed you with me as a filter to clean the harmful particles from that air. If He had not done so, your lungs would fill with soot and dust and they would fail eventually. You would not be able to sense the taste of food because the experience of flavor cannot be achieved by the taste buds alone. It is me that helps them to do that. For instance, a person whose olfactory epithelium has been ruined cannot tell whether it is an apple or a radish that he or she is eating. If you cannot sense the odor of the foods you eat, you will not be able to get their flavor, either.

Dear Peter, I think I have described myself to you sufficiently. I even support your spectacles for you! I have given you brief information without too much detail about my microscopic intricacies. While even one hair inside me cannot be placed by itself, do you think it is possible for me to have formed myself when I am equipped with thousands of intricate elements, each with a reason? Which sculptor, do you think, can make the nose of a sculpture, without a hammer and chisel in his hands and without a model and will in his mind? Other than the belief in God, there is no way of explaining my creation, which is a thousand times more splendid than the making of the nose of a sculpture. So, whenever you wash your face and look into the mirror, examine me carefully again and remember our God Almighty who created us out of nothing.

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

The four main functions required for life, namely the digestive, respiratory, circulatory, and excretory systems are all found in plants but performed by different organs. If these functions are non-existent the dynamism or the essence of existence that we call life will disappear and death is inevitable. If these four functions (digestion, circulation, respiration, and excretion) are in working order, it means an organism is alive but only at the level of plant life. To reach the animal level of life, in addition to the four main functions, functions like senses, nervous and muscular systems are also required.

If these functions fail, life continues, but at the level of plant life. We sometimes hear people saying “in a vegetative state.” When you hear this, people are usually talking about a person who has lost the use of the animal functions. He or she may be unable to see, feel, hear, or move. Intelligence, comprehension, will power, conscience and the many other special aspects of human beings cannot be compared with the essential functions of living; these are additional characteristics of being human which accompany the animal system of functions and emerge in relation to a person’s spirituality. This obviously does not mean that those who have lost their abilities are less human and they do not have any rights; on the contrary, it means to say that they are not responsible any more.

The focal points of sensory functions of sight, hearing, touch, taste, and smell are found within the head in the brain, which is the command center of our body and the most complex form of existence we know of in the universe. The brain is connected to the nervous system which communicates with all the organs in the human body. This is why the head is so precious; it is a very sensitive part of the body and has to be protected like a jeweler guards precious stones. If you tread on a nail, it may hurt for a while, but with treatment the wound can be cured. But if a nail were to penetrate someone’s head, this could damage any of the sensory functions or, God forbid, could even result in death.

As you have probably understood from our introduction, the head is firstly the center of animal functions then the focus point of the addition of the human senses. When you mention the head we are the first thing that comes to mind: the eyes. Did we hear you ask why? It’s because we are what you are reading these words with right now, and because you can see the beautiful creations of the universe with us-that’s why.

If my Creator had not created us and positioned us in the two cavities on your head, you would have no knowledge of the beauties of light, color, insects, flowers, roses or birds. You would be afraid to walk without us because you would have no idea where you are about to tread. The effect of sight can only be sent through us to your brain and reflected into your mind. The development of human knowledge would have been very delayed if God had not created us or the other sense organs because the only way to gain knowledge is through healthy sense organs. The sense organs are the only way of detecting and recognizing the characteristics of objects.

You need us to realize that water is transparent, apples are red, quinces are yellow and violets are purple, you need us to recognize your mothers, fathers and friends. You need us to eat, drink, read and write and so you do not bump into walls. What do you think will happen if we close our lids for ten seconds and you try to walk down the street? Try it if you want!

You see-it was harder than you thought. You were scared in case you bumped into something or fell over. Look, Peter, just take a deep breath and give praise to our Creator while our lids are closed tight, for you could not tolerate being in the dark for a mere ten seconds, so what if you never saw the light? Just think sometimes about people who are not as fortunate as you, who cannot see for one reason or another. Give praise to our Creator for not giving you such a trial, and pray for the patience of those friends who have been deprived of sight.

Yes, now we have come to our characteristics and delicate creation, so pay attention. When Darwin saw God’s magnificent skill in our creation, he realized that we could not have been just a coincidence or a self-made creation, and it was impossible for us to be a creation of unconscious nature. Due to the guilt he felt inside, he found it necessary to say that the idea that “the evolution of complex organs like the brain and the eye could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree.”

There is no artificial optical device that can match the esthetics or precision of our creation. Our operating principles depend on the optical laws God Almighty has determined for the light. As a matter of fact, just by looking at our structure, human beings worked out the rules of optics, you made the simplest of cameras, and you went on to produce the most magnificent photographic cameras possible. But whatever you do, never try to compare one of us to those cameras you have invented or you may become rather embarrassed. Your cameras are a simple toy compared to us. From the time of the invention of the old, wooden box cameras that had to be covered with a black cloth up to the modern digital cameras of the present, 175 years have passed. Many people worked for years to bring cameras to such a perfect state. Can anyone claim that the old camera made of a wooden box and a lens evolved by itself and turned into the high-quality, digital cameras of today? With all the knowledge accumulated by hundreds of scientists over the years, can this invention really be called a coincidence? So, can we be a coincidence? Could the eyes of mollusks or insects make themselves evolve and transform into the eyes of humans? Of course not! But to understand this a little better you must pay attention to our structure.

We are globe-shaped and look like covered capsules with a multi-layered structure which is quite solid and supple (Figure 1). Each of us is approximately 24mm in diameter. We have an outer layer made of something called sclera (hard coating). We are protected by a strong cover made up of dense ligament fibers, and beneath this is the choroid layer (a layer of blood vessels), where the blood vessels nourishing us go into; this layer covers us completely like a network of vessels. In the middle of the eye is the retina which is a layer of film. It is located in the most precious place where our actual receivers of light reside. There are other layers which each have their own duty beneath these layers, but we won’t go into too much detail.

We each have a main casing that is round and has a dome-shaped surface which slightly protrudes. The center of the hard coating, the cornea, is transparent so that it will allow light to pass through. On the outer part of the transparent area is what they call the white of the eye, and the whole areas seen from the front is covered in a clear membrane (the conjunctiva) with mucus cells. This keeps us lubricated. So as to focus light rays, our cornea section is more curved than other sections. There is a tiny chamber behind this curved front and this is actually where the lens, which separates the main chamber, is found. In the front chamber between our lens and cornea is a transparent liquid, the iris, which gives us our color. The black hole in the center of the iris is called the pupil. The iris, which has a special structure of muscles, works like a curtain contracting and expanding our pupil in response to the brightness of light. If the light is powerful, it contracts to protect the retina from any damage, whereas if the light is dim, the iris expands the pupil to allow more light into the retina.

The fibers (zonules) that hold the lens suspended in place and the cluster of muscles (corpus ciliare), which changes our lens according to the focus distance, are in front of a layer of blood vessels. Our lens, which plays a role in focusing, changes shape and adjusts according to whether the focus point is near or at a distance by thinning and thickening. We do this with the help of the fibers that keep the lens suspended.

Behind the lens is a larger chamber filled with a jellylike, transparent liquid (vitreous humor). The pressure and consistency of the jellylike liquid ensure that we keep our round shape. There are photoreceptive cells in the shape of rods and cones which are sensitive to light in the dark chamber behind our retina. The visual images formed by the rays which pass through the cornea and lens to the retina are upside-down. There is a small pit in my retina where almost every cell has a light receptor cell. This is where your sharpest vision is formed, but that doesn’t mean that it is where you actually perceive the object you are looking at. Sight is what happens when a group of cells in the brain’s visual center is stimulated, and the images on our lens are comprehended. It is unbelievable how fast is the effect of the chemical and electro events on our light receptor cells. The effect of light is conveyed to your brain through the stimulation of electric signals in our receptors’ optic nerve where the actual vision is produced in the brain, so in a way we are just the means of vision.

Because we are such delicate and sensitive organs, our Creator placed us in the cavities within the bone structure of your head for protection. We fit in the very strong and secure structure comprising your chin bone, cheek bones, forehead bone, orbital bone (just around us, your eyes), nasal bone and occipital bone (at the rear and bottom of your skull), but this is not our only protective mechanism. We have top and bottom eyelids that we close to protect ourselves from oncoming dangers. The frequent blinking of our eyelids prevents our cornea from becoming dirty, just like the windscreen wipers of a car. Our eyelids are not just simple folds of skin, they are a secretion system of glands which continuously lubricate the inner part of your lashes and seize dirt and dust, turning them into harmless particles. When you feel emotion, the secretion produced by the tear glands between us and the nose fills the tear ducts, passes through the two canals, and gives us a good wash. But when you cry too much, the excess secretion empties through another canal, which also washes your nose.

As this system is complex, it can also go wrong sometimes. If you consider our many parts and our millions of cells you will clearly see the possibility that any one of our components may fail. However, our Creator has formed the eyes in most people’s heads without any defect or failure, so we can serve you with vision of the universe.

The Creator gives us something called illness so we are reminded of our weakness, a defect or failure which arises as an act of wisdom. Some illnesses, like diabetes, deficiency of vitamin A or atherosclerosis, may have a negative effect on us and even render us useless. We eyes also have some defects which occasionally appear, such as not being able to see at a distance, or close up. Focus defects are easily remedied with spectacles or lenses, but faults in the sensitive light receptor cells in the retina are more difficult to amend. The pressure of the liquid in our larger chamber must be correctly balanced. If this pressure increases too much, we will give you a great deal of pain due to what doctors call glaucoma. If we lose our transparency, your vision will become clouded by what is called a cataract. Apart from this, there are many viruses and bacteria that can cause infections and diseases, but the cells of your immune system are like soldiers who, with the Creator’s help, protect you from those bacteria and viruses.

Look, Peter! It would take pages and pages for us to explain ourselves to you, but we don’t really want to confuse you with even more anatomical information. Our whole aim is to explain the reasons for the creation of our parts, to astonish you with the wisdom and fine art of the Divine, so you will contemplate the wonders of creation and give praise to the Almighty for the blessings he has bestowed upon you. If we have been successful in achieving this, that would be the greatest reward we could ask for.

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