CAUTION: Organs at Work - Part II: The Lungs
Since we live in the material world and our cells are made up of atoms and molecules our body must follow the laws of nature. These laws demand that our body follow the rules by making sure its cells have enough energy to do what they need to do to keep us alive and having enough energy requires having enough molecular oxygen (O2). We know that we can't live very long without breathing in air because, unlike water, salt and sugar, our body can't store oxygen, so it constantly needs new supplies. However, clinical experience teaches that respiration involves much more than just making sure the body has enough O2 for its energy needs. It also involves getting rid of enough carbon dioxide (CO2) and controlling the hydrogen ion (H+) content, since both can be toxic to the cell and can cause death. Let's see how the body does it.
Following the Rules
Our cells use O2 and a specific set of enzymes and carrier proteins to break the chemical bonds within glucose to get the energy they need through cellular respiration. In this chemical reaction one glucose molecule (C6H12O6) reacts with six oxygen molecules (6 O2) to produce six carbon dioxide molecules (6 CO2) and six water molecules (6 H2O). The air we breathe in through the lungs consists of 21% O2 and 0.04% CO2. But the air we breathe out consists of only 16% O2 (a decrease of 25%) and 4% CO2 (a 100 fold increase). This takes place because through cellular respiration the cells use up some of the O2 in the blood for their energy needs and produce CO2.
Besides having hemoglobin to carry O2 in the blood, red blood cells also have an enzyme called carbonic anhydrase which takes CO2 and joins it to water (H2O) to form carbonic acid (H2CO3). In the blood carbonic acid breaks up into H+ ions and bicarbonate ions (HCO3-). The more CO2 the body produces from cellular respiration, the more H2CO3 the red blood cells produce and the more H+ ions present in the blood. In fact, 99% of the body's H+ ions come from cellular respiration.
The lungs consist of large airways called bronchi and smaller ones called bronchioles. They are lined with mucous membrane that warms and humidifies the air as it moves into the hundreds of millions of alveoli, deep inside the lung. Each alveolus is surrounded by hundreds of small blood vessels called capillaries. It is within these alveolar capillaries where gas exchange takes place, O2 goes into the blood and CO2 comes out.
For lungs see: http://www.nhlbi.nih.gov/health/health-topics/topics/hlw/system
The main force that makes the lungs breathe in air is the dome-shaped sheet of muscle called the diaphragm which points upwards and separates the chest from the abdomen. The laws of nature determine how air is forced into the lungs by contraction of the diaphragm. These laws state that; the pressure inside a chamber, with a given amount of air or water, is inversely proportional to the size of the chamber. If, the space inside the chamber decreases, the pressure inside increases and if the space inside the chamber increases, the pressure inside decreases.
Think about how the heart works. It fills with blood and then when it contracts, making the space inside the chamber decrease, the increased pressure within the chamber propels the blood out into the arteries. The heart pumps blood by positive pressure. But the lungs work in the opposite way. When the diaphragm contracts, causing it to flatten out, this increases the volume of the chest cavity and decreases the air pressure inside the lungs. When the air pressure inside the lungs drops below the air pressure outside of the body this forces air into them by negative pressure. If you want to get a feel for what this vacuum effect is like, hold your nose and keep your mouth shut and then try to breathe in as hard as you can. The tugging sensation in your head, neck, and upper chest area is due to your diaphragm contracting and being frustrated at not being able to expand the lungs.
For diaphragmatic function see: http://brassmusician.com/the-diaphragm-and-some-common-misconceptions/
Now that you understand how the lungs work, it is important to consider what they must be able to do to keep us alive. After all, experience teaches that life is a dynamic process and when we work and play hard we must breathe harder and faster to give us the energy we need to do what we want to do. This functional ability of the lungs to match our ongoing energy needs would have been the difference between our earliest ancestors eating or being eaten. Darwinists seem to consider only how life looks but not how it actually works within the laws of nature to allow for survival. They assume that just because different organisms have similar structures, they must have all come about only by chance and the laws of nature alone. In contrast, the experience of human invention shows that when encountering a mechanism that allows something to overcome the laws of nature to continue to function, it is much more reasonable to conclude the presence of intelligent design. A car moving up a hill must have a mechanism in place (like a driver or cruise control) to provide enough gas to its engine at the right moment to overcome the forces of nature that prevent it from going over the top and continuing on its way. So too, the body must be able to take control of its lung function to do what it needs to do at the right moment to survive within the laws of nature. Let's look at how it does it.
In general, the body functions best with a blood O2 level above 70 units, a CO2 level of about 40 units, and an H+ ion level between 35-45 units. The further the O2 level drops, or the CO2 and H+ ion levels fall out of the normal range, the more the body malfunctions and the weaker it becomes. In fact, a blood O2 level below 30 units, a CO2 level above 90 units, and an H+ ion level below 20 units or above 100 units, is usually incompatible with life. So you can see that keeping control of the body’s O2, CO2 and H+ ion levels is important for survival. So, how does the body manage to take control?
The first thing you need to take control is a sensor to detect what needs to be controlled. The body has chemical sensors (chemoreceptors) that are able to detect O2, CO2 and H+ ions. Peripheral chemoreceptors for all three of these chemicals are located in the main arteries that send blood directly to the brain. Also, located in the brain, are central chemoreceptors which detect H+ ion. The exact nature of these chemoreceptors and how they work is as yet poorly understood. But just like the gas sensor in the fuel tank of your car, these chemoreceptors are located exactly where they need to be to get the information that is needed to help the body maintain control.
The second thing you need to take control is an integrator which interprets the information from the sensors, compares it to a standard, makes decisions about what needs to be done, and then sends out orders. The data from these O2, CO2 and H+ ion chemoreceptors is sent to the respiratory center in the part of the brainstem called the medulla. The respiratory center analyzes this information and sends out nerve messages to the muscles of respiration. How the respiratory center “knows” what the O2, CO2 and H+ ion levels should be so the body can live and function properly is a as yet a complete mystery. But just as the gas sensor in the fuel tank must be connected to the right gauge on the dashboard and be properly calibrated, so too, the data from these chemoreceptors must be sent to the right place and be interpreted correctly for life to survive.
Nobody really understands how these chemoreceptors work or how they must have come into being simultaneously and be positioned in the right place for life to continue. Clinical experience teaches that loss of control of any one of these three chemical parameters results in death. Nor does anyone really understand how the respiratory center inherently knows what the levels of O2, CO2 and H+ ion should be for us to survive. So with such a limited understanding of the first two components needed to take control of O2, CO2 and H+ ion in the body, how is it that evolutionary biologists can be so certain that human life ultimately came about by chance and the laws of nature alone? Do you think that the sensor inside your fuel tank, which is connected to the fuel gauge on your dashboard, came about by chance and the laws of nature alone? But, we still need to look at the third part of what’s needed to take control.
The third thing you need to take control is an effector which receives the orders from the integrator and does something. The nerve messages from the respiratory center go down the spinal cord and exit the neck through the phrenic nerve to the muscles of respiration which makes the lungs breathe air in and out. But when it comes to lung function, real numbers have real consequences. Clinical experience tells us that when it came to lung function the numbers had to be just right for our earliest ancestors to have survived because when they aren't right debility and death is the result.
Real Numbers Can Mean Life and Functional Ability
When the body is at complete rest it uses 250 milliliters per minute (mL/min) of O2. Slow walking requires 500 mL/min, fast walking 1,000 mL/min, and moderate running about
2,000 mL/min. To be maximally active, like what our earliest ancestors would have needed to prey upon others and avoid being preyed upon, the body needs to use at least 3,500 mL/min of O2. Being able to bring that much O2, in through the lungs, would have been the difference between life and death. Here’s how it works in practice.
As noted above, at complete rest, the body uses about 250 mL/min of O2 to work properly. Think of it like how much fuel a car uses when it’s idling. It needs a minimum amount of energy just to get the pistons in the engine going while the oil lubricates the moving parts and the anti-freeze circulates to keep everything cool. The same thing applies to the body as well. It needs a minimum amount of energy just to maintain adequate brain, heart, lung, kidney and liver function just to name some of the more important organs. The tidal volume is the amount of air breathed in and out with each breath. For most people, at complete rest, the respiratory center sets the tidal volume for each breath at about 500 mL and the respiratory rate at 12 breaths per minute. Let’s see if that’s good enough to get the 250 mL/min of O2 the body needs at rest.
We first need to realize that about 150 mL of the tidal volume (500 mL) includes the airways which aren’t directly involved in gas exchange. So, at complete rest, the amount of air the alveoli actually receive with each breath would be about 350mL (500 - 150). A respiratory rate of, 12 breaths/min, would result in the alveoli, receiving 4,200 mL/min (350 mL x 12) of air. But since O2 only represents 21% of the inspired air this means that the amount of O2 the alveoli receive would be about 880 mL/min (4,200 x 0.21). Finally, it’s important to realize that the alveoli do not take all of the O2 out of the air and put it into the blood. In fact, only about 30% of the available O2 crosses into the circulation. So the amount of O2 the blood receives would be about 264 mL/min (880 x 0.3). This matches almost perfectly with the amount the body needs at complete rest (250 mL/min). The respiratory center certainly seems to know what it’s doing!
Any increase in O2 use by the body, above 250 mL/min, is generally due to digestion and in particular, physical activity. To stay active our body needs to use more O2 to give our muscles the energy they need to overcome forces such as inertia, gravity, friction and wind resistance. For maximum activity, the type our earliest ancestors would have had to have done to stay alive, the body requires at least 3,500 mL/min of O2. Experience teaches that the respiratory center must know what’s required and the respiratory system must be able to do it, otherwise we wouldn’t be here. However, medical science still doesn't understand how the respiratory system adjusts fast enough to allow for maximal activity as it seems that this function goes beyond just being able to match up the O2, CO2 and H+ ion levels. But of course, the fact that we really don't know how it works does not stop evolutionary biologists from claiming that it all came about by chance and the laws of nature alone. Let’s see what it takes and how the respiratory system does it.
If the body is very active and in need of increased O2, then the accessory muscles of respiration will swing into action. These muscles, located in the neck, the shoulders, the upper back, and the abdomen, assist the diaphragm and the muscles between the ribs, to expand and contract the chest cavity as much as possible. Try breathing heavily and notice which muscles and what parts of the body you‘re using. For the non-athletic person, the volume of air they can send to their alveoli with moderate activity is about 60 liters/min. But since inspired air only contains 21% O2, this would mean that the amount of O2 delivered to the alveoli would be about 12,000 mL/min (60,000 x 0.21). And since 30% of the O2 in the air that is breathed in crosses into the circulation this means that the amount of O2 sent to the blood would be about 3,600 mL/min (12,000 x 0.3). This would have been exactly what our earliest ancestors needed (3,500 mL/min) to prey upon others and avoid being preyed upon. So, it would appear that not only does the respiratory center know what it’s doing, but the respiratory system itself, has a natural survival capacity for life.
Think about the different parts of your respiratory system, how your diaphragm brings air into your lungs by negative pressure, and how your respiratory center inherently knows what your blood levels of O2, CO2 and H+ ion should be to keep you alive. Then ask yourself if what evolutionary biologists say about how you came into being makes any sense? You can see that the respiratory system must have given our earliest ancestors the right numbers to maintain a functional ability to survive. But just as a defective car can have problems with performance (or not work at all) so too, defects in lung function can lead to loss of control and result in debility and death. That’s what we’ll look at next.
Real Numbers Can Mean Dysfunction, Debility and Death
Auto mechanics are called in to fix a car when it does not perform up to expectations or especially if it cannot run. They have ways of testing the car’s different functional parts to see if there is something wrong. Is the flow of air or fuel compromised? Is cylinder compression a problem? Is the transmission working right? Each of these parts can be objectively tested and the result can often be reduced to a number. This number can then be compared to a normal standard and can therefore tell the mechanic whether the part is working properly or not. With this numerical information the mechanic can determine whether this part could be affecting the car’s overall performance. Once the problem has been discovered, possible remedies and prevention can be implemented.
Much like the mechanic and the car, medical science has developed ways of testing different aspects of lung function to see what may be going wrong. Is airflow in and out of the lungs compromised? Is there a problem with lung expansion and the volume of air the lungs can hold? Are oxygen and carbon dioxide being exchanged efficiently enough? Each of these aspects of respiratory function can be objectively tested and the result reduced to a number. This number can then be compared to a normal standard which will help medical personnel identify what may be the problem. Once the problem has been discovered, possible remedies and prevention can be implemented.
One of the measurable parameters of lung function looks at the velocity of airflow and is called Forced Expiratory Volume within one second (FEV1). Recall that in physics the velocity is determined by the distance traveled in a certain amount of time. Instead of distance over time the FEV1 measures the volume of air expired over time. This gives medical personnel an objective reading of how fast someone is able to move air in and out of the lungs. The person is instructed to take in a maximal breath and then blow it out as fast as they can. The amount of air released in the first second is the FEV1 which normally is about 3 to 4 liters.
Assuming the presence of no other physical limitations, someone with a normal FEV1 should be able to perform at maximum activity levels. But a drop in FEV1, to 2-3 liters, results in mild physical impairment, such as difficulty running quickly. Having an FEV1 of only 1-2 liters causes moderate physical limitation, making it difficult to walk quickly. And an FEV1 below 1 liter causes severe physical impairment, being unable to even walk slowly without moderate shortness of breath.
In a car, fuel and air movement to the engine can sometimes be impaired by obstruction to flow. This can be due to things like a clogged air or fuel filter, or a blocked fuel line. In a similar way, the airflow velocity in the lungs can often be affected by obstruction to flow which can be reflected in a drop in a person's FEV1.
People who smoke cigarettes often develop chronic bronchitis, which is part of chronic obstructive pulmonary disease (COPD). This takes place because the cigarette smoke chronically irritates the mucosal lining of the airways causing it to swell and thicken. This often results in excessive mucus formation and surrounding muscle tightening (bronchospasm), especially when stressed by infection. Mucosal swelling and bronchospasm act to reduce the diameter of the airways causing obstruction to airflow. This manifests itself in the smoker with coughing, congestion, wheezing, difficulty breathing, and a lowering of the FEV1.
Asthma is another example of a condition that can result in airflow obstruction from mucosal thickening and bronchospasm with the same symptoms mentioned above. Asthma causes acute and generally reversible obstruction to airflow. It usually occurs when a person with allergies becomes exposed to certain pollens, chemicals, or infective agents. People who have asthma and smoke cigarettes are particularly at risk of attacks of airflow obstruction which can result in very serious functional impairment. Moreover, people with serious chronic obstructive lung disease are always at risk of losing control of their O2, CO2 and H+ ion levels. This can happen especially when they develop either a respiratory infection or some other non-respiratory medical problem, such as a heart attack, a stroke, or a generalized infection. In general, any condition that weakens the body, and causes a reduction in muscle strength will make it more difficult for the person with COPD to breathe. Moreover, this will cause a further drop in the O2 level and a rise in CO2 and H+ ion levels, resulting in a downward spiral that can often lead to death.
Another objective test of lung function looks at the overall functional lung volume and is called the Forced Vital Capacity (FVC). The normal total lung volume is about 5-6 liters but it never fully deflates and generally maintains a residual volume of about one liter of air. To measure the FVC, the person is instructed to take a maximal breath in and then forcefully breathe out for as long as possible. The total volume of air, which is normally expired within 2-3 seconds, is called the FVC. This represents the effective functioning lung volume and is usually about 4-5 liters.
Similar to the FEV1, as the FVC drops, so does a person’s functional capacity. This results in increasing shortness of breath and physical limitations as the body tries to maintain the proper levels of O2, CO2 and H+ ion. The number and size of the cylinders in a car’s engine determines its capacity for power. Even if the air and gas flow to the engine is adequate, if one or more of the cylinders is not working properly, then the car’s power becomes compromised. Similarly, even if there is no obstruction to airflow, if the lungs have any limits to volume expansion, then the ability for the body to obtain enough O2 and release enough CO2 and control its H+ level will be compromised.
Medical conditions which result in this limitation of lung expansion are categorized as restrictive lung disease (RLD). One common example is related to the bony structure that surrounds the lungs. The lungs reside within the chest cavity which is made up of the breast bone up front, the ribs at the sides and the thoracic spine at the back. Any deformity of this bony structure may result in restrictive lung disease. Some people develop a condition called kyphoscoliosis in their late teens, and older women in particular are prone to osteoporotic and degenerative changes in the thoracic vertebrae, causing a limitation of chest wall expansion and a reduction in the FVC. In addition, any condition that produces weakening of the muscles of respiration will result in a restriction of lung expansion and a drop in the FVC as well. Some examples of these neuromuscular disorders are polio, muscular dystrophy, myasthenia gravis, Lou Gehrig’s disease, and Guillain Barre Syndrome. These people are often short of breath even at rest and have difficulty being active. When affected by a lung condition like bronchitis or pneumonia, they often suffer from marked debility which can even result in death due to the inability to maintain control of their O2, CO2 and H+ ion levels.
One other objective parameter of lung function that is often measured to determine the capacity of the respiratory system is the diffusion capacity. This assesses the efficiency of the alveolar tissue to exchange gases across the capillaries to and from the circulation. Carbon monoxide (CO) is a gas that is known to pass readily from the lungs to the bloodstream, even better than O2, which is why exposure to too much of it can quickly result in death. To test the diffusion capacity of the lungs the person inhales a very small amount of carbon monoxide and then exhales. The expired air is then analyzed to see how much CO was removed by the circulation and is expressed as a percentage of normal. This is known as the diffusion capacity of the lung for CO (DLco). Similar to the FEV1 and FVC, as a person’s DLco drops from 100% toward 50% or lower the ability to maintain the right levels of O2, CO2 and H+ ion is compromised. Consequently these people develop increasing shortness of breath with limited activity.
All of the parts of a car’s transmission combine to efficiently convert the power generated in its engine’s cylinders to the wheels, causing motion. This is literally where the rubber meets the road. So even if the engine has no obstruction in its air and fuel system, and its cylinders are working to full capacity, if the transmission is not working properly then car performance will suffer. Similarly, the lung's equivalent of where the rubber meets the road is where gas exchange takes place within the alveolar capillaries. Even if a person’s FEV1 and FVC are normal, if the DLco is very low, indicating a problem with gas exchange, then their breathing capacity is going to be severely compromised.
One common condition that causes this diffusion problem is pulmonary fibrosis which falls into the category of interstitial lung disease. The cause is often unknown, but can occur with auto-immune diseases, in which antibodies to lung tissue develop in the body. The result is a thickening (fibrosis) of the alveolar cells interfering with gas exchange. However, by far the commonest cause for a reduced diffusion capacity is smoking-induced emphysema. This takes place due to years of cigarette smoke and its various toxic hydrocarbons causing destruction of alveolar tissue resulting in major problems with gas exchange. Just as for a person with a low FEV1 or FVC, if they have a low DLco then they will often be chronically short of breath with minimal activity. Also, if they suffer a respiratory infection such as bronchitis or pneumonia, it is likely to result in a serious compromise in O2, CO2 and H+ ion control and which can lead to death.
In summary, auto makers know that the specifications of the different components making up a car, such as air and gas flow, the number and size of the engine’s cylinders, and the transmission, determine its performance capacity. So too, medical science can show that in order for our earliest ancestors to have survived long enough to reproduce, the specifications of their lung function would have had to have been just right. They would have had to have had normal air flow (FEV1), functional capacity (FVC), and efficiency of alveolar gas exchange (DLco). But there is still one more aspect of lung function that needs to be considered by evolutionary biology. It's the respiratory center in the brainstem that tells the lungs to work, but what does it take for a respiratory arrest to occur? After all, when the lungs don't breathe in a new supply of O2 or get rid of a build-up of CO2, this results in a high level of H+ ion called respiratory acidosis which causes death.
Evolutionary theory claims to explain how life came into being by describing only how life looks but not how it actually works within the laws of nature to survive. But we must now consider what actually causes the lungs to stop breathing air in and out resulting in death. Now, if you were trying to figure out how life came into being, wouldn't you think that understanding how the body dies of respiratory arrest would be an important place to start? Like knowing all the different ways a car can die and then working backwards to figure out how to prevent them from happening? If you think about it, that's exactly how the control systems in the body are set up; to prevent not only cardiac but also respiratory arrest as well.
A respiratory arrest is the sudden cessation of breathing and is distinct from a cardiac arrest which is the sudden stoppage of effective cardiac output where the heart is no longer able to provide enough blood flow to sustain life. Respiratory and cardiac arrest often occur simultaneously (cardiopulmonary arrest), but if separate and left untreated, they invariably lead one to the other in quick order. The lack of O2 and the quick rise in the CO2 and H+ ion levels due to a respiratory arrest usually causes irreversible vital organ damage (particularly in the brain) within just a few minutes. Recall, it is the respiratory center located in the medulla within the brainstem that tells the lungs to breathe. So when a respiratory arrest takes place, if breathing is not restored within a few minutes the cells in the respiratory center die and the body no longer has anything to tell it to breathe. At the same time the cells in the rest of the brain, and soon after, all of the other vital organs, including the heart, die as well. The final result is irreversible death.
Airway obstruction causing enough blockage so that enough air cannot pass in and out resulting in a significant decrease in O2 and increase in CO2 and H+ ion will cause the cells in the respiratory center to malfunction and result in a respiratory arrest. Upper airway obstruction caused by choking on a foreign body, like food, or particularly in infants and children, a small toy, is one example. Another is a tumor or swelling of the tissues in the upper airway due to infection or an allergic reaction. Common causes of lower airway obstruction include aspiration, drowning, pneumonia, and the build-up of interstitial fluid within the lungs due to acute congestive heart failure (pulmonary edema).
Diminished respiratory effort so that enough air cannot be moved in and out of the lungs resulting in a significant decrease in O2 and increase in CO2 and H+ ion will cause the cells in the respiratory center to malfunction and result in respiratory arrest. This can take place due to disorders of the brain, such as trauma, stroke, infection or tumor. Included here is cardiac arrest since it results in no blood flow to the brain. Metabolic disorders resulting in diminished respiratory effort leading to respiratory arrest include severely low blood pressure or levels of glucose, calcium and sodium. Also, this can occur due to excessive doses of sedatives, such as alcohol and heroine, and medications for pain such as opioids (morphine, oxycodone and hydrocodone) and anxiety and insomnia, such as the benzodiazepines (lorazepam, alprazolam, temazepam). Finally, neuromuscular disorders, such as polio, Lou Gehrig's disease, myasthenia gravis and Guillain-Barre syndrome, either from severe progression or complications can cause enough diminished respiratory effort to result in respiratory arrest as well.
When it comes to trying to understand how human life came into being, we are now entering the credibility zone. For in trying to explain how the lungs are able to provide enough O2, get rid enough CO2 and help control the H+ ion level the body needs to live within the laws of nature, evolutionary biologists are faced with a Catch-22 situation. Not only are the lungs made up of cells, but so are all the organs and tissues involved in providing the control mechanisms needed to allow them to function properly in the first place. In other words, the lungs are dependent on their own function for survival because all of the systems in the body that control chemicals like oxygen, glucose, water, sodium, potassium, hydrogen ion and things like clotting, blood pressure and temperature, are also made up of cells that are dependent on the lungs providing enough O2, getting rid of enough CO2 and helping to control the H+ ion level so they can do what they are supposed to do.
The universal human desire to know the truth requires us to go beyond just describing how life looks, as evolutionary biology does, by digging down deeper to understand the actual mechanisms behind how life works within the laws of nature. The lungs and the organ systems that control its function, being made up of different parts, are irreducibly complex, but clinical experience teaches that that just isn't enough to explain how life came about. As this article and others have shown, the body must take control to follow the rules imposed on it by the laws of nature because real numbers have real consequences and are a matter of life and death. And to do this it needs to have natural survival capacity, an inherent knowledge of what those numbers should be and be able to do the right things well enough at exactly the right times to stay alive.
Not only does life need the information present in its DNA to make everything it needs to come into being, it also needs other information to allow it to survive within the laws of nature as well. As Stephen Meyer stated in The Information Enigma, the cause in operation that drives life is information, particularly digital or typographic information that experience tells us comes from a mind and not a material process. It is indeed unfortunate that evolutionary biologists, who claim to know the truth about how life came into being, and control what students are taught about it, do not seem to understand this most fundamental of principles.
Be sure to catch all of the articles in Dr. Glicksman's series, "Beyond Irreducible Complexity."
Howard Glicksman M. D. graduated from the University of Toronto in 1978. He practiced primary care medicine for almost 25 yrs in Oakville, Ontario and Spring Hill, Florida. He now practices palliative medicine for a Hospice organization in his community. He has a special interest in how the ethos of our culture has been influenced by modern science’s understanding and promotion of what it means to be a human being.
Comments and questions about this article or any of the previous ones are welcome.
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