Introduction to The Respiratory System

The respiratory system is responsible for providing oxygen required for body cells. It has the function of carrying carbon dioxide waste. The muscular and skeletal systems are tasked with movements that make breathing possible. This is an efficient structured organ system, yet it has its weaknesses. The air can contain various particles, microbes, or allergens that can be hazardous to health. The respiratory system has delicate structures that are susceptible to severe damage. Respiratory disorders are among the most common of illnesses. Air that is inhaled transports to the trachea through the bronchi reaching the lungs. There are a total of two lungs in the human body. Each lung contains bronchioles, which are tube like in structure. These pipe structures cluster in alveoli The gases migrate the alveolar walls both to and from blood vessels. The intercostal  muscles as well as the diaphragm beneath the lungs allow for air to be drawn in and out. This happens in a particular time interval. Air enters through the nostrils and thus begins the process of respiratory function.
    The respiratory system contains both a upper and lower tract. The upper tract contains the nose, nasal cavity, paranasal sinuses, and pharynx. These networks of passages warm, filter, and humidify outgoing air. The lower respiratory tract houses the larynx, trachea, bronchi, bronchioles, and alveoli. Breathing requires respiratory reflexes. The brain's respiratory centers.Receptors must process the sensory information arriving that are sensitive to oxygen, carbon dioxide, and acidity levels present in blood and cerebrospinal fluid. Receptors are also delivering information to blood pressure receptors and stretch receptors in the lungs. This either lets it be known their is pain or nasal irritation. Breathing pattern can change in rate depending on the behavior of receptors. This can prevent the lungs from over inflating or act as a defense mechanism against harmful matter in the air. Breathing is a subconscious action, but emotions can change it. Feeling nervous could cause a person to breath fast than when they were calm. The common respiratory reflexes include coughing, sneezing, yawning, and hiccups.

These reflexes are reactions to the environment.  Coughing forcefully releases air from the lungs in order to clear the airways. Cough receptors will become irritated by inhaled particles or large amounts of mucus. Once the trachea and bronchi are cleared, normal function resumes. The cough happens with a deep breath causing the glottis to close entrapping the air in  the lungs. The diaphragm including other muscles contract. The result is pressure causes the glottis to open once more forcing out the contaminants. Mucus droplets aid in the elimination of bacteria and other particles. Coughing acts as a defense against foreign air born material that could be harmful to the body. Sneezing also acts in a similar manner. When irritation occurs from inhaled particles, odors, or infection large amounts of inhalation happen. The glottis closes while a person's eyes will close as well.  Contraction then causes air to be expelled from the nose and mouth. Yawning is involuntary and is learned even during embryonic development. It is a common trait among all vertebrate animals. When blood levels are showing an increase in carbon dioxide more oxygen in dawn into the lungs. Blood oxygen levels increase. Yawning may also allow for blood to cool while passing through the brain. 

Another know respiratory reflex are hiccups. These are nothing more than involuntary contractions from diaphragm. Hiccups could be evidence of the human evolutionary past when our early amphibious ancestors went between land and water. The glottis closing would have stopped water from going into the lungs and push it out through gills. A human fetus even hiccups and contains gill like structures. Surrounded by amniotic fluid  this helps protect the lungs from fluid getting inside of them. Hiccups are primarily induced by nerve activity that controls the muscle in the diaphragm.  

      The respiratory system  has specific structures that have various functions. The larynx has the role of securing the entrance to the trachea and housing the vocal cords. The larynx consists of nine pieces of cartilage. This includes thyroid, cricoid, epiglottis, arytenoid, corniculate, and cuneiform cartilages. The larynx is situated between the pharynx and trachea. The thyroid cartilage forms a mound beneath the skin of the neck. This is known as the laryngeal prominence ( Adam's apple ). This structure is more pronounced in men than in women. The cartilage is secured by support from muscles and ligaments. The hyoid bone acts as an anchor for the muscles supporting the larynx.Internally the larynx is a hollow chamber and this enables air to enter during breathing. The cartilage will tilt moving vocal cords producing speech.  What appears to be a simple process relies on a network of various structures. Branchioles  and air sacs are also important to the respiratory system. There are two main bronchi which are subdivided in the lungs. The right bronchus forms three secondary bronchi. The left bronchus only forms two. Gas exchange happens at the terminal point. 

    The pleural sacs are found as enclosed shields  lungs. They have two layers which contain parietal wall and a visceral wall. The visceral wall is located  beneath the lung, while the parietal is attached to the chest of the wall. This explains why the lungs are able to slide over the chest wall during breathing. The thin layer of lubricated fluid  that divides pluera enables this process without harm to the lungs. The diaphragm dome like in shape is a muscle that separates the chest and the abdomen. Along with the intercostal muscles these are the primary muscles that contribute to breathing. This reduces pressure on the thoracic cavity. This means the lungs have the ability to expand downward. The lower respiratory system has a lining which is a moist mucus membrane. Bronchi lined with columar epithelium are contributors to moving particles out of the lungs. The cilia of the columar epithelium act as an remover of possibly hazardous substances. This is an example of internal protection, but the body's twelve ribs act as a shield for the lungs and heart. The lungs are the most recognizable structures of the respiratory system. The human body has a total of two, which are cone structured in appearance. There is a difference between the right and left lung. The right lung as three lobes, while the left has only two. This allows for room for the heart. The right lung is only a little bit larger in comparison and averages 60% of lung volume. The pharynx is a structure that allows moistened air to pass through the throat. There are also other auxiliary structures that  collaborate in air passage. The nasopharynx enables the passage of air. Both the oropharynx and laryngopharynx  permit safe passage for food and various fluids. The concha present in the nasal cavity from the etmoid bone. This forms three ledges, which capture air borne particles and can increase the surface area of the naval cavity. 

    The respiratory system also enables phonation. This is the process of  an individual to produce speech sounds form the vocal cords. The vocal cords are made from two folds of mucus membrane stretched horizontally across the larynx. It is connected to thyroid cartilage in the front. The arytenoid cartilages are the support in the back. When the vocal cords close when  air coming through during exhalation, this causes vibration . The result is sound produced. These are just a few of the basic structures of the respiratory system. 

     The lungs are on the largest organs in the body and central part of the respiratory system. The lungs contain alveoli, which are clump like structures. Elastic and thin walled they have the shape of grapes. Macrophages are present on the outer surfaces. Macrophages are white blood cells responsible for protecting against air borne irritants. The alveoli also have  networks of capillaries. When oxygen comes through it gets into the blood by diffusion. Then it travels through the alveolar and capillary walls. Carbon dioxide diffuses another way from the blood into the alveoli. There is a total of 300 million alveoli present in the lungs. They provide a huge surface area  for gas exchange. It is estimated to be forty times greater than the body's surface. The pulmonary venule will take fresh high  oxygen blood, while the pulmonary arteriole gives used low oxygen blood.  The apex of the lung is the upper point, which projects just above the clavicle. The left primary bronchus is narrower and longer compared to the lobar bronchus. The lobar bronchus has to form one of two air ways. The segmental bronchus has to aerate the broncopulmonary segment. The pulmonary arteries must bring deoxygenated blood from the heart. The pulmonary veins have to send oxygenated blood to the heart. There is a total 30,000 terminal bronchioles in each lung. They branch out into either two or more respiratory bronchioles. The lungs are hard at work being the area of  gas exchange. 

         Oxygen is drawn into the body through the lungs. The process of gas exchange in the lungs starts with oxygen from the air dissolving into fluid lining  in the alveolus. It will then disperse through the blood capillary wall and alveolar wall. Oxygen  then shall enter the blood plasma and will bond with hemoglobin. Carbon dioxide will then diffuse from blood plasma and goes in air in the alveolus. The red oxygenated blood makes the journey through the aorta by pathway of the arteries reaching the body's tissues. Thin capillaries then are required to transport oxygenated blood. The newly delivered red blood cells the bind to  the body of each cell. The oxygen will  leave hemoglobin in the red blood cells. The diffusion will result in hemoglobin in the blood capillary walls and into the tissue cells. Carbon dioxide diffuses into the tissues of the cells, wall of the blood capillary and ends with going into the blood plasma.  

Cellular respiration also occurs in the human body. Blood sugar known as glucose is the body's primary energy source. Cellular respiration happens in every body cell when oxygen interacts with glucose. The result becomes energy released in chemical form. The product made form this is carbon dioxide and water which is called metabolic water. There is a difference in aerobic capacity between the sexes. Men have on average larger lungs and hearts, which give them higher aerobic capacity. Besides that there is no difference in the respiratory system between men and women. 

       Breathing is essential to organisms with a respiratory system. Bodily respiration is tasked with taking in air capturing oxygen, while removing used air and waste product through carbon dioxide. The actual movement depends on pressure in the lungs and the atmospheric pressure of the environment. The pressure differences occur due to an expanding chest and muscular action. The sternocledomastoid is a muscle that has to pull the clavicle and sternum upwards to enlarge the chest cavity. The pectoralis minor pulls the third. fourth, and fifth ribs in the body. The scalenes must elevate the upper ribs. Other muscles such as the external intercostals also contribute. The need to breath is dictated by the function of the nervous system. The brain stem generates responses on how best to regulate breathing. Breathing can alter the volume of the thoracic cavity. The lungs can become larger depending on inhalation or exhalation. Inhalation requires the use diaphragm, ribs, external intercostals and the sternum. This can enable the chest to expand, while the lungs can be stretched. Exhalation seems more passive in labor and action. The lungs recoil when the diaphragm, intercostals, and other muscles come to a state of relaxation. Abdominal pressure moves the diaphragm upward in the process. The lungs are then compressed to a point beyond the usual resting volume. Pressure can either be classified as either positive or negative. Negative pressure involves lung volume increasing as air pressure decreases. This means atmospheric pressure which is external is higher resulting in air being sucked in . Condition for positive pressure involve lung volume decreasing when exhalation occurs. Pressure is built up in the lungs causing air to be pushed out. This explains why air come out through the mouth and nose. This is the basic function of the respiratory system. Like other organ system it collaborates with other to the biophysical machine known as the human body.  

References 

Brewer, Sarah. The Human Body A Visual Guide To Anatomy. London: Quercus, 2012.     

  

Parker, Steve. The Human Body Book. New York : DK Publishing, 2013. 

The evolving story of human evolution | Melanie Chang | TEDxVictoria

Melanie Chang discusses the history and science of 8 million years of human evolution. Humanity is the last of its species. Humans have only been around 200,000 years. Neanderthals went extinct and homo sapiens were the lone survivors. Paleoanthropology has to be reliant on field work and fossils. It is not possible to revive neanderthals and study them in a natural history context. However, genetics has allowed some breakthroughs. Mitochondrial DNA provides some clues. Scientists in Germany found out that humans contain 1 to 4 % neanderthal DNA. This indicates there was possible cross breeding. Human are still evolving and this has been proven to be fact. evolution will no longer be just a theory, but a fact like the universal law of gravitation. There is resistance to new discoveries with the most religious thinking human evolution is not possible. Doubtless of conviction, facts are true whether you like them or not. The story of human evolution is still being revealed. The puzzle will only be complete when the common genetic ancestor is discovered for all primates.   

The Technological Apex

Technology has radically changed society. Transportation, communication, and economic services have become more efficient at any point in human history. Science continues to make advances in astronomy, physics, biology, medicine, and computer science. At some stage in evolution of technological advancement there will be an apex. This means that civilization will have reached such a mastery of science and technology that it cannot advance any further. Disease will not be an issue to public health, space travel will be a part of daily life, and quantum computers could be in every household. These notions may seem exaggerated, but what was once science fiction has become reality. Airplanes, spacecraft, automobiles, and super computers have become a part of human society. If the world decides to put emphasis on rationality and progress the future could be a better place. There is a possibility that such advancement to civilization could be lost to warfare, civil unrest, or severe climate change. History has demonstrated that not only ideas, but technology has changed society to an enormous degree. The turning points were the rise of philosophy, which evolved into modern science, and from there applied science. The industrial revolution, modern medicine, mathematical theory, physics, biology, and chemistry allowed for the modern marvels of the contemporary era. This vast knowledge  could easily be lost, which has occurred during periods of instability.    If this can be avoided, then civilization will reach a technological apex. The rise of the technological apex will be the most significant development in human history. World civilizations at that stage will be able to control the environment, resources, and even the very nature of life itself.
   Transportation has become more prevalent. Air planes, automobiles, trains, and space craft move humankind everywhere. The last and final step in the revolution of transport will be space travel. So far humankind has been able to the reach the Moon. The year 1969 was the time in which humanity went into space. The next destination, with enough effort will be Mars. There are technical challenges. Traveling beyond our Solar System could be extremely perilous. Radiation levels and lack of  gravitation on a spacecraft could effect the body. Long term health effects are still unknown. This must be understood if humanity is to travel long distances in space. Besides merely traveling, there should be plans for possible terraforming. The Moon and Mars could provide a great testing area for such experiments. Astronomers have discovered that there are Earth like exoplanets beyond our Solar System. If spacecraft becomes more advanced, these areas could be colonized. The long distance traveling space craft would have to be efficient in fuel and durable in structure. Traveling to areas that are thousands of light-years away would take many lifetimes. The possible method for fast travel would be to either manipulate traversable  wormholes or produce a ship with high speeds. Until these astrophysical barriers are  circumvented, astronomers have to depend on satellites and powerful telescopes. While space travel is still in a prototypical phase, the automobile industry will undergo a revolution.

Cars reliant on oil and gasoline will become obsolete. Electric cars and other means of fuel requirements will replace it. The only problem is that the automobile industry does not want to invest in it. Fossil fuels are a finite resource, so it is only logical that change will happen. This leads to other possibilities. Hover cars may be made available. They may not reach high altitudes, but enough to not require wheels. Hover boards could be made, yet there are some technical obstacles. Electric cars will be the cars of the future and be more efficient compared to fossil fuel vehicles. This type of car may be easier to maintain and have more durability. The fear is that consumers would stop buying more cars, if they lasted longer. Such a claim is not true, because a car to some people is a status symbol. Consumerism will never end and the public's appetite for new technology is always growing. Self driving cars are in the early stages of development. It will not be unusual to see drivers having their own cars drive without their hands on the wheel. The computer systems of such cars would have to be ensured that it cannot be hacked. To an extent this does pose a safety and security risk. As long as the drive has the ability to gain steering and brake control when they see fit, it should be fine for consumers. 

There will at some point be more high speed rail for land transport. The locomotive will not become obsolete. Instead more trains will be maglev rather than metal rails. There are only a few maglev trains that are active in some countries of the world. They will eventually become the standard. Japan and South Korea seem to be more open to the technology, while countries like Germany, Canada, and the UK have had them at various periods. The United States if it wants to reach a technological apex must invest in this technology. Trains that are maglev move more smoothly and this could reduce the risk of accidents. Subway systems could be constructed to meet the technological needs of such trains. Ultimately, this will reduce costs in terms of maintenance of transport systems. Maglev trains will be faster and more efficient than the traditional wheel and rail trains of the past. This will also impact commerce making shipping less of a burden. 

Aircraft will also undergo a revolution in design and capability. Fighter jets are becoming more sophisticated in terms of speed and mobility. The development should not focus solely on military purposes, but on commercial transport. The majority of research aviation technology is directed to that purpose, yet there should be more emphasis on safer  and fuel efficient planes. There are many engineers who are designing planes that appear like something out of science fiction. Humanity has conquered the sky and land in a short period of time. The march of technological advancement started with the development of simple machines, the tools of the Paleolithic and Neolithic era, and the creativity of the human mind. Yet, one should not jump to rapid conclusions or predictions about the future. While futurology is an exciting field, it tends to predict events that are either outrageous or exaggerated. The technological apex is not a prediction, rather a teleological narrative about where this technology might lead humanity. Relative to transportation, people will be more mobile than ever before. Migration is nothing new to humanity. Our australopithecine ancestors traveled by foot from Africa later to spread across the world. There has been a desire to move and settle. Humanity has mastered the skies and land, but the sea floor still seems like unexplored territory. There are many species of marine life that could be unknown. Submarines and submersible craft can only go so far due to the intense ocean pressure. Mastering full transport of land, air, sea, and the final frontier of space will take human civilization to another level. 

      Biomedical science has progress to a rapid degree. Organ transplants, safe surgery, and the understanding of health science. These advancement will eventually lead to life extension. This has happened to a degree, with more people living into old age. Stem cell research will lead to an efficient method of producing new organs without a donor. Genetic engineering will become more prevalent. Genetically modified organisms are already present in society. Plants and various sustenance are considered  genetically modified organisms. There remains a fear that with the power of genetic engineering a transhumanist future will take over. This is not about enhancing humanity with unnecessary modifications, but conquering disease. Genetically inherited diseases could be eliminated through genetic engineering. This could also lead to possible cures or better treatments for neurodegenerative diseases. Dementia and Alzheimer's disease can be cured through advances in cytology. If medicine progresses so far humankind may find the key to life. There holds the possibility that death can be transcended. If the physical and mental decline of senescence could be reversed life may not end. The problem is that this could cause social and political issues. Achieving immortality or eternal youth seems more like stories of legend and myth. From a point of biological evolution, physiology, and health science immortality would be impossible for humanity to achieve.Age and death are a part of the biological life cycle. Disease may not be completely subdued, however it can be reduced. Antibiotic resistant bacteria has increased in number causing major health concerns. Mental illness from a neuroanatomical   perspective is still a mystery. Brain scans such as computer axial tomography, magnetic resonance imaging, and positron emission tomography have discovered an immense about of information about the human brain. This exploration into the human brain and mind is a significant development. Understanding the most complex organic computer will finally answer the question what it means to be human. This has been a question of philosophy and religion; only recently has this question been answered in a scientific context. 

  

The more that is learned about human evolution, the more humankind understands itself. Advances in genetics can help us understand the past. Medicine will be better with few side effects and tailored better to a person's health condition. If new technologies are used responsibly they can improve the human condition. 

     The subatomic world also is a realm that needs further exploration. It is only a matter of time before the nature of various particles are fully comprehended. As a result the way societies consume energy will change. Solar and wind power are going to be a new part of energy production. However, fusion reactors will replace fission reactors. This means nuclear power could be made safer and meltdowns will no longer be a threat. A combination of  both wind and solar power including fusion reactors with meet the energy needs of a rapidly growing global population. Fossil fuel dependency no longer will hold back nations. Although the fusion rector is in a phase of development Germany and the UK have been doing research into such power generation. Besides mere power generation the discovery of the nature of matter sparks more wonder and curiosity. The higgs boson explains why matter has mass, but that is only a part of a much larger puzzle. Particle accelerators allow physicists to confirm various particles, even without mathematics to indirectly prove their existence. Theoretical physics will no longer just be hypothetical in nature; it will be fully experimental. The standard model could see expansion. There is a diminutive world of quarks, muons, leptons, taus, and neutrinos. Understanding such a small world allows for  the advancement of nanotechnology. 

   Machines that are nanometers in size could have various applications. The possibilities could range from surgery, construction, or manufacturing. This is more efficient than drilling for oil or mining coal. These fuel sources are finite and are near depletion. The political and international consequences of this could be devastating, unless action is taken. Investment in new forms of energy and the development of new technologies is the only rational solution. Harnessing the power of the sun could sustain human populations. The wind and solar cycle can be used to the world's advantage. For now the type 2 G star sustains the Earth. These technologies at some point could become prevalent. There still remains a level skepticism about their effectiveness and the business interests devoted to fossil fuel.

     Computers and information technology has come to dominate daily life. Video games, virtual reality, and the internet have created an entire industry of electronic entertainment. Another element to the rise of cyberspace is how it has changed culture. Communication has become more rapid and the average person has more exposure to knowledge. Mass amounts of information can be transferred to people in seconds. Computers went from being the size of an entire room, to the size of a phone. Computer power has increased rapidly, but the evolution will not stop. The next impressive milestone in computing will be the rise of the quantum computer. Currently the quantum computer is in its development stage. They are not like electronic computers that are reliant on transistors. Companies such as Google are already making such machines. This new type of computing manipulates quantum mechanical phenomena, which will perform operations in regards to data. This functions on measurements of qubits. Commercialization will follow and the public may have even faster and more powerful  computers. Mathematics as will gain from this in terms of theoretical research. Calculations of complex theorems or problems will be simple for a computer of this power. If computers are increasing their power, then artificial intelligence may follow. Robotics are a part of industry, yet they do not have the ability to learn. Learning, memory, and problem solving are attributes of intelligence. 

    

There could be in the future androids that are human like with intelligence . They could even have self awareness and sentience. What may seem like a fantasy, becomes more real as technology advances. The economic and political impacts could have some negative repercussions. The labor of robots could replace the work of man. There could be the possibility of revolt among the conscious robots against their creators. Automation poses problems for the workforce, but not the financial elite. These issues would have to be addressed before such technology is introduced. Regulation and certain laws would have to be enforced to ensure no abused would occur. While technology does improve life to an extent, the prospect of abuse becomes higher. 

      The technological apex is not a prediction of the future. It cannot be said the the future will look Bladerunner  or Startrek . These fictional representations show what the creators think the future might be like. However, invention would not be possible without imagination or creativity. Too often it is forgotten that ideas for technology had to thought of through a long process. Early versions of machines and their prototypes either were failures and required multiple attempts. Sometimes discoveries are pure accidents. The technological apex describes how far human civilization can go in terms of  the manipulation of technology and scientific discovery. Once it is reached, there may be nothing left to create. Human civilization may not even reach this level of development for a number of reasons. While there is advancement in science, the world is backward in many regards. Warfare, racism, and religious fundamentalism are a demonstration of  this backwardness.Before any of this level of technological advancement can be reached ideological and philosophical convictions must be changed. The new wave of anti-science sentiment must also be challenged. Ignoring facts such as climate change, human evolution, or environmental science can no longer be acceptable. The public and the wider society must learn to distinguish fact from fiction and most importantly be critical thinkers. A society that is too dogmatic and closed minded will never reach higher levels. The public has a suspicion about science that stems from either fear or lack of understanding. Technology generates this same emotion. Technology is a tool that can either be used for positive or nefarious purposes. It is a choice that people make and the societies in which they live make. The only way the technological apex can be reached is if humanity uses it to improve the human condition. Technology has become ubiquitous in world civilization and it will continue to spread. If humankind can survive it will reach a point of vast knowledge and power.   

     

2017 Total Solar Eclipse

The 2017 solar eclipse was the first to be seen in America since 1918. What is displayed are photographs of this rare occurrence. The cosmos continues to fascinate humankind and captivate the curious . These photographs show the beauty of  outer space and the stars the populate it. 

Scientific Notation

Scientific notation is a method used to work with large numbers in regards to particular measurements. Smaller numbers can also be expressed in scientific notation. Writing numbers in their full form would be too cumbersome a task when doing calculations with  immense numbers. Numbers that reach sizes of  trillions or more can be manipulated easily by a mathematical method. The expression for scientific notation is recognizable by a base number ( which can be referred to as mantissa) multiplied times ten raised to a certain power. Exponents are critical to producing scientific notation. The exponent determines the amount of decimal places in the number in notation form. When the exponent is negative, different rules have to be applied. 

A negative exponent requires the decimal point to be directed to the left. A positive exponent means that the decimal point shall go to the right. Zeros will be added as needed for the correct expression. Scientific notation follows five rules. A number written without an exponent has the number 1 for the exponent in the notation. The second rule requires that any number ( excluding zero 0 or 0 raised to the zero power) with an exponent of zero is equal to one. It should also be noted that a power demonstrates how many times a number is multiplied by 10. 

The key to writing correct scientific notation is to understand place value. If the decimal point is moved to the left the power of ten will be expressed as positive. When the decimal point is transported to the right the power of ten will be negative. These are the general rules for the proper format for scientific notation. The larger the numbers become it will not be a problem to express them in an efficient manner. Numbers that range past a trillion would be tiresome to write in full form. Quadrillion contains 15 zeros, quintillon has 18 zeros,  and at maximum the number decillion contains 33 zeros. These numbers expressed would look like this : 1,000,000,000,000,000 (quadrillion),1,000,000,000,000,000,000(quintillion),and1,000,000,000,000,000,000,000,000,000,000,000 (decillion) . Doing basic arithmetic or algebra would be frustrating if one had to continually write long numbers like this. Science is not meant to be complicated,but simple and efficient. Scientific notation is another extension of that concept. This mathematical method of expressing values is helpful for astronomy and astrophysics when discussing magnitude and distance . 

Further Reading 

Barnes-Svarney, Patricia L. "Scientific Notation." The New York Public Library Science Desk Reference. New York: Macmillan, 1995. 3-4.