Think of a kitchen. This kitchen has a blender for blending, an oven for cooking, a fridge for cooling, utensils for eating, a dishwasher for cleaning, pans for frying, jars for storing, peelers for peeling, etc. It has a full line of tools, gadgets, and appliances for the sole purpose of helping us prepare a meal. However, they are all separate appliances that altogether fill up an entire room. The fridge is not connected with the oven, nor do the forks have anything to do with the blender. Now, think of such a kitchen in which all of these gadgets and appliances work together in perfect harmony. The fridge cools some strawberries and passes them to the blender, which blends them into a tasty juice. The blender then pours this juice into a glass and serves it to you. After you are done drinking, the dishwasher kindly asks for your glass and washes it before putting it back into your cupboard. Oh, by the way, this kitchen fits snugly into your backpack so you can have juice on the go. This sounds a bit too good to be true, doesn’t it? How could every appliance be in perfect sync with all the others? How would it keep itself clean? How could all of this equipment be so compact? There would be so many complications and barriers to building such a system.

Now, what if I told you that such a system has already been built? And it’s not just a kitchen; it’s an entire palace. Our body is a marvelous palace with millions of functions and features. Such a purposeful design must have certain principles, some of which are efficiency, cleanliness, ease-of-use, and unity. Everything within our body is interconnected and works in total sync. Each organ plays its own crucial part and together they perform amazing feats. In this article, I will try to write about one player on this team: our lungs.

Our lungs serve a very important purpose: to provide the energy our body needs. Our body is in a constant state of activity. Even when we sleep, our heart pumps, our kidneys filter, our liver detoxifies, and our brain computes. No organ really ever shuts off. Maintaining such a machine is no easy task and it requires a constant source of energy. Each cell has its own generator and is more than capable of producing its own energy. However, a few things are needed to keep these generators running, one of which is oxygen. Every cell in the body needs to be constantly served oxygen as their operations begin to get disrupted only within a few minutes of an oxygen shortage. We know that our blood is full of this miracle gas, but how does it get there in the first place? We all know that it gets there through our lungs, however it is not that simple! The air that reaches our lungs cannot be too much or too little, too hot or too cold, or too dry or too wet. It has to be just right! There are impeccable mechanisms in play to perfect the conditions for each and every breath. Now, take a deep breath and keep reading!

Let us begin with how we bring air into our bodies in the first place. When we take a deep breath we actually control our diaphragm, not our lungs. The diaphragm is a membrane-like muscle that separates our abdomen from our chest cavity. It is the muscle that we move downwards when we initiate a breath. The bases of our lungs are stuck onto our diaphragm; so when we move our diaphragm downwards our lungs are also pulled down and increase in volume. This sudden increase in volume generates a negative pressure inside of our lungs causing air from the atmosphere to pour in. In addition, our exhalation occurs on its own without using any energy! Our lungs are very elastic, meaning they “want” to return to their original form similar to that of a rubber band that will snap back to its original position after getting stretched. So, after we stop contracting our diaphragm our lungs shrink back to normal and exhale air in the process. Furthermore, since breathing is semi-automatic we contract our diaphragms without even thinking about it. Most of the time, our brainstem takes care of this process without even bothering our brain. Imagine if we had to willfully inhale and exhale every breath; we wouldn’t have much time or concentration to do anything else! As you can see, this life-or-death mechanism is extremely cost-efficient and uses very little energy and little to no brainpower.

Mouth and nose

Moving onward, the beginning of the journey of air, in relation to our bodies, begins with the mouth and nose. Air is dry and its temperature can vary greatly depending on where we live or which season it is. Our body’s core temperature must be kept at a certain level for it to function optimally. Even if we wear the thickest jacket during winter, the air we breathe finds its way into the center of our body. If it weren’t for our nose and mouth this air would quickly dry up and chill our lungs. Tiny blood vessels on the surface of our nasal mucosa provide the majority of the warmth for the air that enters our nose, and the amount of blood flowing through them is regulated based on the heat of the air we breathe: more blood for colder air and less for warmer. These blood vessels also provide the moisture that is picked up by inhaled air before it enters our lungs. In addition, since the air we exhale is already warm and moist part of that moisture condenses back onto the mucosa before leaving our body. Just like a mirror fogs up when we exhale onto it, our nose and mouth are moistened with every exhalation as well. This simple, yet efficient, system is able to warm and moisturize every single breath we take while making sure no drop is wasted!

Cilia

Now, let us venture a bit deeper into our respiratory system. Unfortunately, the air is not sterile and is full of billions of microorganisms floating around. Therefore, we inevitably take in hundreds of thousands of germs with each breath. Lucky for us, but not so lucky for these germs, our respiratory tract is covered with mucus and lined with thousands of “cilia.” Cilia are specialized tentacle-like extensions found on the cells all throughout our respiratory tract. These tentacles constantly grab germs from the air, just like a dust roller grabs dust from a rug. Not only do they grab germs, they push them back outside of our lower respiratory tract. This pushing motion is performed in the form of synchronous waves by all of these tentacles and brings our germ-filled mucus back to our throat. From there, it is typically swallowed into our stomach where the acid melts it away. If we are sick and have an increased load of mucus, emergency measures like coughing or sneezing assist to evacuate the excess. Only certain bacteria that are resistant to being captured by our cilia make it into our lungs and quite a few need to penetrate our defenses to lead to an infection. Our respiratory system greatly exposes itself to the environment by taking in thousands of liters of air every day, and each breath can be considered an attack wave of bacteria and viruses. Yet, it manages to keep itself sparkling clean and ever-vigilant for the next wave.

Lungs

We finally made it to our lungs! Our respiratory tract was able to draw in the dry, cold, germ-infested air from the atmosphere, warm it, humidify it, clean it, and carry it to our lungs. After this long journey (that lasts a few seconds), it is finally time to extract that valuable oxygen! For this extraction to occur air needs to come in contact with blood vessels. The larger the area of this contact is, the better. Our lungs are designed to maximize this contact by distributing the air to a large surface area. When we take a single breath, which is about 3 liters of air, it is distributed to a surface area of nearly 70 m². This is possible because our trachea (windpipe) branches out many many times to eventually form over 700 million tiny air sacs called alveoli. This masterful dispensation allows us to extract the maximum possible amount of oxygen from each breath and deposit it into our blood. By the way, as if it was known ahead in time that many people would adopt harmful habits like smoking, lungs are made to branch into many more alveoli than we need to live, to prepare for possible damage.

In addition, the amount of air taken in with each breath is also carefully regulated. Our lungs are very flexible and can accommodate twice as much air as the typical three liters we take in with each breath. Our brainstem has a respiratory control center that automatically adjusts the speed and volume of our breathing according to the amount of oxygen we need. Running a marathon? The settings are cranked up to high. Fast asleep? Well, then you don’t need so much, so they are set to low. Our brainstem is tasked to sense our need and nurture us accordingly each and every second, and we do not need to worry about it. Try to imagine if this process was left to our management!

Our lungs also keep a small amount of air that is left inside no matter how hard we try to exhale. This volume of air is called the “residual volume” and it keeps our lungs from collapsing, which would prevent air from entering the lungs. By keeping our lungs even a tiny bit inflated at all times, we drastically reduce the energy required to breathe in. The process is similar to how blowing the first mouthful of air into a balloon tends to be the hardest, and how the continual mouthfuls are easier and easier. Just like a balloon our lungs keep that first mouthful inside at all times so the rest is always easy to fill up. This is why a deflated lung is such a big problem, because it is nearly impossible for a person to re-inflate it by themself. It usually requires assistance from a medical ventilator to get the lung back to normal.

This article only covers a few of the hundreds of mechanisms taking place in our lungs all the time so we can survive. Each of these mechanisms performs many functions, and none of them contradict each other. On the contrary, they all work in perfect unison to provide us with a nice big breath of air. However, there are so many other micro and macro mechanisms at the atomic, cellular, organ, and system levels that constantly carry out millions of functions in our body. They all follow the same principles of efficiency, cleanliness, ease-of-use, unity, and so many more, and all come together as one living, breathing, thinking, and loving human being. Doesn’t that just take your breath away?

The human body is built from the elements found on earth. There are approximately 44 kg of oxygen, 14 kg of carbon, 7 kg of hydrogen, 2.1 kg of nitrogen, 1 kg of calcium, and lesser amount of other elements existing in a 70 kg human body. In fact, many of the 92 naturally occurring elements can be found in the human body, which resembles a small universe. Surely, these elements cannot act chaotically and only fulfill their duties in the organs that are assigned to them in the great mechanism of the human body.

Oxygen is one of these natural elements; under normal natural conditions, it exists in gas and molecular form (O2 and O3). It is abundant throughout the world: nearly 65% of the human body, 88% of the waters on earth, and 46.7% of the earth’s crust are made from oxygen atoms (in terms of their mass). Since it is an active element, which makes compounds with many other elements, it is found generally in compound form.

When we say oxygen, the first thing that comes to mind is the oxygen we breathe in the air. The volumetric ratio of atmospheric gases are 78% nitrogen (N2), 20.9% oxygen (O2), 0.93% argon (Ar), 0.04% carbon dioxide (CO2), and lesser amounts of water vapor and other gases.

Oxygen is the most vital requirement for organisms that carry out aerobic respiration. To sustain life, nutrients must be converted into energy in our cells. Therefore, oxygen obtained via respiration must be carried to the cells. The amount of oxygen intake and tolerance time without oxygen varies among living things. Studies have shown that humans can live around 3 to 4 minutes without oxygen; the brain begins to shut down after 5 minutes without oxygen.

The jobs of gases during respiration

Respiration is a wonderful mechanism which is dependent on the nervous system; it is autonomous and usually takes place with ease. The respiration rate for adults is 10-15 times per minute; for children, 20-30; and for infants, 30-40. Respiration can simply be defined as the replacement of carbon dioxide gas in the blood with oxygen. Approximately 400 million alveoli in the lungs are where the oxygen and carbon dioxide exchange takes place. The oxygen that passes into the blood here is transported to cells when it binds to the hemoglobin of the red blood cells. The oxygen, which is captured by the iron (Fe) in the hemoglobin (Hb), is then released for the cells.

Roughly 4/5th of the air inhaled during respiration is nitrogen; 1/5th is oxygen. If we only need oxygen, why do we inhale other gases? It is because the integrity of air plays a critical role in breathing (the oxygen-carbon dioxide exchange). The gas ratio of air before and after respiration is given below.

As seen, while nitrogen and other gases remain constant, oxygen levels decrease, whereas carbon dioxide increases. Only 5% of the inhaled air, or oxygen, is consumed. For our cells to receive the sufficient amount of oxygen they need, the total gas pressure, composition, and oxygen concentration in the air must fit these variables. In addition, water vapor that mixes into gases inside the respiratory track assists with the regulation of gas pressure in our lungs.

The rate of gases in the air is finely tuned. If there is less oxygen in the atmosphere, aside from its many negative effects in nature, it would be insufficient for respiration; the amount of oxygen that passes into the blood to bind with hemoglobin would not be enough for our cells, and the excessive oxygen would also be toxic. For example, mountain climbers use oxygen tanks; as elevation increases, air pressure and oxygen decrease. Excessive oxygen, however, may cause loss of consciousness (coma), nausea, cramps, and visual impairment. Concentrated oxygen can be fatal for cells. According to Australian biologist Michael Denton, each extra 1% above the current 21% ratio of oxygen in the atmosphere would increase the possibility of a lighting based forest fire up to 70%.

The vital role of nitrogen

Under normal conditions, nitrogen is found in nature in its gas form as an inert element. In other words, it is created so that it only reacts under rare and special circumstances. It does not react with many substances, such as water, air, acids, and bases. Is there any function for nitrogen gas in our respiratory system?

When nitrogen gas enters our body via the air passage, it is exhaled back without getting into any reactions in our lungs, blood, or with oxygen. It does not affect the oxygen we breathe in; however, it plays a role for adjusting oxygen’s rate. Its presence is necessary for the respiration of oxygen under certain concentrations, flows, and pressure.

What would happen if any of the inert gases – like helium (He), neon (Ne), argon (Ar), or krypton (Kr) – replaced nitrogen? Not only could these gases not substitute for nitrogen with their physical and chemical features, but they could also not carry out its other functions. For instance, their solubility in blood under pressure is different. Therefore, vital problems such as decompression sickness because of different air and water pressure conditions would be seen more often, especially for pilots and divers. Also, because of different absorption and reflection rates in sunlight, our climate and other species would be affected. Furthermore, the nitrogen cycle takes part in terms of the maintenance of life on earth as outlined by natural laws.

It’s plain to see that the balance of elements and gases on our planet, and in the whole universe, have been perfectly balanced to sustain life. It seems remarkable that our planet could be created in such a way as to support so many creatures, who require such a specific balance to survive.

Before anasthesia, even routine surgeries were painful and dangerous. Its advent has allowed for amazing advances in public health and patient safety.

Humanity has faced various kinds of health problems throughout history, and will be facing them until the end of time. Even someone who has not yet suffered from an illness, will almost certainly suffer from one in the future. Let’s take a moment to reflect on all the people who are currently undergoing treatment at hospitals in the hopes of curing an illness.

From time to time we visit close friends and relatives who have undergone such operations. We wish them health and talk with them a little. We ask them how the operation felt, how many stitches they have. They usually say, “They injected me with something and I don’t remember the rest.” Then they may show us their gall bladder, wrapped in gauze, or their kidney stone, which was removed. Have you ever pondered how it is possible not to feel any pain during these kinds of operations, or how it is possible not to remember anything?

Surgical practices have advanced so much in present times. Heart, liver, and kidney transplants are now commonplace, as are finger and arm reattachments. Anesthesia, which makes all of these operations possible and painless, is a great blessing. Even the small and simple surgeries performed just 150 years ago were very difficult for surgeons – not to mention very painful for patients.

In his famous book on physiology and treatment, The Canon of Medicine the renowned 10th and 11th century scholar, Avicenna (Ibn-i Sina) (980-1037), defines anesthesia as, “a numbing and a cooling remedy.” He gives pathophysiological commentary on the influences of anesthetics and analgesics, and summarized painkilling methods as following:

1. A mixture prepared from linseed and dill should be applied to the area of pain.
2. Decreasing the sensitivity of the area of pain by increasing the moisture of the area, or providing narcotics for sleep.
3. Providing cooling and analgesic and anesthetic medicine.

Biruni, another Islamic scholar from the 11th century, documented his work with analgesic and anesthetic medicine. One of his writings recommends boiling the root tubers of henbane, Mandragora, horned poppy (Glaucium flavum), and Iris, together with the attar of roses and vinegar.

In his pharmacological works of the 12th and 13th centuries, Samarqandi recorded the analgesic, sedative (calming), anesthetic, and hypnotic effects of opium, mandragora, henbane, lettuce, beaver testicles, aloe vera, and coriander.

During the end of the 17th century, in Italy, anasthesia was performed by preventing the patients from breathing until they lost consciousness, and then immediately performing surgery on the patient who had fainted. This was called the asphyxia technique. The surgeries performed were relatively easy, such as the cutting of an arm or leg. The surgeon who was fast was considered the best, because patients could wake up during the surgery – that is, if they survived the procedure.

Another interesting anesthetic technique was making the patient lose consciousness by hitting them on the head. The hitting had to be done, “Hard enough to break the shell of an almond but gentle enough not to destroy its seed.” However, a bitter truth is that many patients were killed during this process.

Many have suffered the consequences of the absence of anesthesia in the past. Dr. Warren, a professor at Boston’s Massachusetts General Hospital in 1846, had placed his operating room on the very top floor of the hospital in order to avoid disturbing others with the screams of the suffering patients. One day, while examining one of patient’s tongues with pliers and a scalpel, he pulled the tongue of the patient without warning, and cut off his tongue with the scalpel. Afterwards, without hesitation, he cauterized his patient’s tongue with a hot iron. Dr. Warren observed the screaming, moaning, and suffering of the patients with no sign of emotion. He did not seem disturbed, and this was the exact attitude he needed in order to perform his duty. However, years later when enough advancement was done in the area of anesthesia, he couldn’t hold back his tears during the first operation that was performed with anesthesia.

Surgeries performed without anesthesia were hard on surgeon and patient alike. During his studies, the English gynecologist, Doctor James Young Simpson, fainted while cutting off a breast and considered quitting being a surgeon. Prof. Dr. Robert Liston was a famous surgeon at London University College. Dr. Liston had a reputation for being rude, arrogant, and strong. But he had no choice: he was forced to cut off a leg in 28 seconds, as anesthesia was not yet developed.

As can be seen from these examples, the absence of anesthesia, and the incredible suffering of the patients, pushed surgeons to be incredibly fast and emotionally insensitive. This period of time defined surgeons as strict, insensitive, and despotic. This went on until 1846, when William Thomas Morton performed the first surgery with anesthesia.

Since then, anesthesia has made surgeries much easier for all involved. Today, the definition of general anesthesia is total or partial loss of sensation in a human or animal body before surgical intervention.

Usually, anesthesia is performed by injecting medicine into the blood, or by making a patient breath an anesthetic gas. First, the patient loses consciousness, and then, with the help of muscle relaxants, the patient is put in a state of paralysis. Artificial respiration is performed until the end of the operation with the help of breathing machines called ventilators. For this purpose, an endotracheal tube is inserted in the windpipe of the patient and they are hooked to an anesthesia machine. This feeds oxygen, air, and the anesthetic gas to the patient. The anesthesia doctor controls the patient’s breathing, blood pressure, and heart rhythm, as well as other various, vital parameters, and the fluids that will be fed to the patient throughout the surgery. By doing this, the continuity of the anesthesia is made possible. When the surgery is over, the anesthetic drugs are no longer fed to the patient. When the muscle relaxants lose their effect and breathing returns to normal, the endotracheal tube is taken out and the patient is taken to another room to wake up. This is where the patient opens their eyes; it’s almost like a re-birth.

The chemicals in cannabis, opium, and coca were the essence of the first drugs used for general anesthesia; they are still being used, partially, in modern times. These chemicals, and some synthetic chemicals like them, are used for anesthesia and can be used after surgery in order to soothe pain. Most of our contemporary drugs are mostly synthetic, and they require many years of difficult education to be properly handled. It takes four years of additional education, after medical school, for a surgeon to become proficient with anesthetics.

Medical research done in the last two centuries about the dosage and quantity of these chemicals has advanced the practice of anesthesia incredibly. All this research provides a very good answer to why drugs have been created. While surgeons use the chemicals extracted from cannabis, opium, and coca, and from the synthetic chemicals like them, as a service to humanity, it is really hard to understand why some ill intentioned people use them for the detriment of human health.

I am placed inside your chest cavity as two air sacks-or bellows-surrounded by your muscles. I took my first breath right after birth and I still keep working non-stop. Even while you are sleeping, I fulfill my function with the automatic command I receive from the respiratory center at the back of your brain. My close friend Heart started working even before me while you were in the womb. I was resting then; actually I hadn’t even formed fully. As all your needs like food and oxygen were met in the body of your mother-whose heart you occasionally break-I didn’t have to make extra effort to get air, being filled and emptied. Even if I had attempted to do so, I would have had no chance of succeeding; since you were contained in the amniotic fluid, an attempt to breathe could have caused you to drown.

The first breath I take after birth is critical and rather difficult, since the windpipe is still much narrower than normal. On the other hand, the number of my alveoli where oxygen exchange with the capillaries is realized is so high in relation to body size that it balances the situation. When I make my first move and fill with air, I put pressure on the arteries and veins. Then the vessel directly connecting my artery to my mother’s aorta is dismissed, the curtain between the valves is closed and the blood circulations are separated. If this curtain is not properly closed and a gap remains in between, the oxygen-rich blood and the used-up blood mix and result in the disease known as cyanosis-or “blue baby” syndrome. As these two kinds of blood mix, the tissues are not supplied with sufficient oxygen and the white parts of the skin and eyes assume a bluish appearance.

Turning blue-purple due to lack of oxygen in the tissues is the same for smokers. Cigarettes-my archenemy-contain hundreds of toxic substances, such as carbon monoxide, which combine with the hemoglobin in blood and prevent oxygen transfer. Therefore, the lips of smokers turn slightly purple. You need to be careful with the air you inhale. The windpipe which brings air into me is covered with a ciliated epithelial tissue which catches the dust brought along and sweeps it outside. While you are asleep, the vibrating cilia of this sweeper work throughout the night and in the morning you get rid of the outcome of their propulsion by clearing your throat. However, every draw of a smoker kills 800–1,000 of our ciliated epithelial cells. After some time, they become unable to sweep the toxins (carbon, sulfur, lead, etc) inhaled with the air. I can’t stand it anymore! The increased air pollution is already putting enough strain on us… this habit is just too much for a lung to handle! It is just… an open invitation for cancer! Sorry, Peter, I didn’t mean to be rude. I appreciate that you don’t smoke, but I wish those who do would realize how splendid a mechanism they are destroying.

Now let me tell you about what a work of art I am. As you also know, art in a structure becomes more meaningful with functionality. As is the case with my other friends with which I work in your body, I am perfectly made to fulfill my duty. In other words, never mind forming an organ like me as a consequence of molecules and cells accidentally coming together, even a single protein molecule in my structure does not come to existence through unconscious causes.

With every breath you take, the pressure of the oxygen within the air inhaled rises, so it passes through my membranes by diffusion and into the adjacent capillaries; there it combines with hemoglobin molecules. At the same time, the carbon dioxide passes through the same membranes into me, and I dispose of it. Both of these are easier said than done! You breathe 13–14 times a minute and the whole thing is repeated over and over. As I keep expanding and contracting during breathing, which you are unaware of most of the time, first of all I need to be very flexible. Together with this flexibility, my most important quality is having the largest possible surface area within the smallest volume. My surface area of around 100m2 (as large as a tennis court) is made to fit into your chest cavity in the form of thin membranes so that my large surface allows gas diffusion. These membranes need to be kept wet; a special fluid is secreted as a precaution and respiration is realized smoothly. Without this fluid, my membranes would just stick together, unable to carry out their duty.

You can compare the course of the air inhaled to that of a car passing from a highway onto increasingly smaller roads and in the end reaching a dead end in the small sacks named alveoli. The air coming in through the mouth and nose unites at the expressway named the trachea, or the windpipe, which is 15cm long and 2–3cm in diameter. Incidentally, I have a couple of things to tell you about the way you breathe. As a matter of fact, inhaling is the duty of the nose. I’m sure it also has a lot to say as well, but let me just mention a simple fact about it. Now, you should inhale through your nose, so that the air you take in gets warm, wet, and is cleaned from dust. If you try to breathe this way, you do not trouble me much, and reduce the risk of catching a cold or an infection of upper respiratory system. Inhaling through the mouth helps dust and germs get into me and you might contract various illnesses from bronchitis to pneumonia. Now you know why kids who have adenoids who sleep with their mouth open get ill so easily. Sorry, I couldn’t help speaking on behalf on the nose.

Well, what were we talking about before that? Oh yes! The ways through which the inhaled air passes. As the name suggests, the windpipe which makes the air reach me is a cylindrical tube surrounded by 16–20 cartilaginous rings. As it is placed beside the esophagus, one side of the rings is made of soft cartilaginous tissue instead of hard, so that they don’t hinder swallowing. The muscular tissue near these rings helps them widen and narrow during respiration or coughing. I sometimes warn you by making you cough. Maybe it seems to be a disturbance, but if I don’t push out air by coughing through the contracted windpipe, contaminants can clog me up and cause you to suffocate. Therefore, the burst of air-what you call a cough-is a great blessing to you.

The sound system at the tip of the windpipe is another wonder. The used air I send out vibrates the cords in that voice-box and produces such melodies, gives voice to such speech! The air divides into the two lungs. My two sides are not symmetrical; the one on the right is divided into three, and the one on the left into two. I think this was meant to make room for the neighbor on the left, the heart. In addition, if there’s any cancer growth in me, the diseased part can be taken out by an operation and I can keep on functioning. God knows the wisdom behind this form. After that, these main bronchi separate into 8–10 thinner branches, like highways connecting to narrower roads. This branching resembles a tree turned upside down. At the tips of these thin branches are the respiratory bronchioles resembling clusters of grapes. The small spheres which make up the cluster are the end of the road and are the most vital parts. These spheres named alveoli are made of very thin membrane and they are surrounded by a net of capillaries (picture 5). These are the functional spots where gas exchange is realized.

I hang in the thorax with veins and arteries all around. There are two layers of protective membrane over me. One of them is stuck on me, whereas the other is stuck on the ribs which form the chest cavity. There is a fine and slippery fluid in between these two layers and it neutralizes the friction every time I inflate and deflate. If it hadn’t been placed there, I would wear out and be damaged. As I inflate during inhalation, the chest cavity should expand simultaneously to make space for me. If it weren’t given a flexible form, I would fail to breathe and you would eventually die. Fortunately, the protective set of ribs and their connection with the spine are flexible enough to make me work comfortably. In addition, the dome-shaped muscular partition (diaphragm) separating the thorax from the abdomen contracts and pushes down the organs in the abdomen. Thanks to the simultaneously programmed movement of both the ribs and the diaphragm I inflate with air and expand.

Being in constant contact with the outer environment makes me susceptible to various diseases. Coughing is among the foremost signals I give in the case of disease, and sometimes-excuse me-I produce a mixture of blood and phlegm. Also, I may have difficulty in breathing and warn you with chest pain. You should be alert to my signals. If bacteria and viruses infect me, they might reproduce inside my air sacs, and cause stiffening and suppuration.

I am particularly sensitive to allergic disorders. When the straight muscles on the walls of my bronchi contact an alien substance, pollens for instance, the consequent histamine secretion makes my muscles contract. In addition, allergic diseases, which can affect blood vessels, affect me a lot since I happen to be one of the major organs contributing to blood circulation. As a result of the contraction of my bronchial muscles and difficulty in disposing of the mucus I secrete to defend myself, I have trouble with breathing-you call it asthma.

In addition to this, we can mention diseases like emphysema, acute or chronic bronchitis as problems I frequently face. Even your anger has a great impact on me. Breathing becomes more difficult immediately.

Peter, I’m sorry, it is not possible to summarize a work of art like me within a few pages, but I need to stop now… but please, keep away from polluted areas and cigarette smoke! Send me as much fresh air as you can. And even though you mostly take me for granted, like my other teammates, please reflect upon what a blessing I am.

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