The main function of the respiratory system is to supply oxygen to the blood so that it can supply it to the whole body. To do that, we need to breathe. When we breathe, there’s a passageway where we inhale oxygen into our lungs, and finally into the blood while we exhale carbon dioxide. This exchange of gases is the respiratory system's means of getting oxygen to the blood. To get oxygen into our blood, there’s a more in depth process in our respiratory system to help us do so. Miss Dayman, an intern who teaches exercise science at Campbell Collegiate shared with us every step of the process of the respiratory system. “Starting from the first breath we take, air goes through the nose where it is filtered, warmed and moistened and the cilia which are nose hairs filter the air that comes through the nose to remove dust and other particles. The air then travels to the pharynx at the back of the throat to the larynx which contains the vocal cords at the beginning of the trachea (also known as the wind pipe) and is where the air travels to next. Trachea also has tiny hairs to get rid of any other particles or fluids before the air enters the lungs. The Trachea divides into two branches, one in each lung. These branches have smaller branches that are attached call the bronchioles. The bronchioles end in tiny air sacs called alveoli which allow for fresh air to get to the capillaries. The air flows through the alveoli and the capillary walls to the blood vessels while the carbon dioxide transfers from the blood stream and into the air sacs where they are then released from the body when we breathe out.”
To have a better understanding of how breathing works, here's a video that will explain it in a visual way.
During the process of breathing, also called ventilation consists of two phases. There’s inspiration and expiration. The diaphragm is a major respiration muscle that helps us with inspiration and expiration. “The diaphragm is located directly below the lungs, along with the intercostal muscles. The diaphragm is a large, dome-shaped muscle that contracts and flattens during inhalation, which causes the chest cavity to expand. This maneuver creates a vacuum which pulls air into the lungs. During exhalation, the diaphragm then relaxes, returns to its previous shape, and air is forced out of the lungs” Miss Dayman shared. The diaphragm and other muscles in your chest and abdomen muscles will change the space and pressure inside our body cavity to accommodate our breathing.
Since now you know what happens in the respiratory system and the role of the diaphragm, it’s time to discuss how physics relate to breathing. When breathing, physics occur when “pressure and vacuum like movements occur in the diaphragm in order to have the breath coming in and out.” Not only that, there’s also the physics of volume that occurs in our respiratory system. As we breathe, our diaphragm pulls down, and it is making room for the lungs to expand which increases the volume of the thoracic cavity and lowers the internal air pressure compared to atmospheric air. The air pressure is greater outside of our body which means air flows from a region of high pressure to a lower pressure. When our diaphragm relaxes, it moves up and the cavity inside your body gets smaller as well as the volume which is forcing air out of our lungs into the atmosphere.
We know since breathing relates to pressure and volume, there must be calculations that can be done to determine these numbers. There are many calculations that can calculate the pressure and volume of our diaphragm and lungs inside our body, but they are never precise. There’s the pleural pressure which calculates the pressure between the chest wall and the lungs. One of them is Boyle’s Law. He suggest that at a continuous temperature, the pressure of the gas differs with the volume of gas. If the pressure or volume changes and if the temperature remains constant, the product of pressure and volume remains constant. There’s also Charles’s Law that states that if pressure is constant, the volume of a gas and its temperature vary proportionately. If either temperature or volume changes and pressure remains constant, then the two gas laws can be combined into the general gas law.
Also, there are ways to calculate the capacity of air breathed in and out from a normal breath, but as always, they are never precise. Miss Dayman said: “on average, people ages 12-18 with a healthy young adults lungs take 12-20 breaths per minute with a capacity of 6 liters of air. Although that is what researches have proven, it is never accurate because it also depends on age, gender, height, weight, and lifestyle (smokers etc.).” Speaking of lifestyle, it is never good to have a smoking lifestyle because that can harm your lungs and heart. Smoking can risk hundreds of diseases including lung cancer and heart disease.
When we're breathing, we aren’t aware of what’s happening inside our body to let us breathe. We take things for granted and don’t know the importance of how science like physics and biology can relate to what we do in our everyday life. People who don't have any health problems don't even think about breathing. When comparing to people who have lung problems, asthma and etc., they always have to think of their health and breathing when we don't. Science is everywhere around us including our bodies. Without science, we wouldn’t know how things function, which would result to not knowing how to solve the problem. The understanding of science involving the respiratory system is just the start. There’s plenty more to learn.
Websites:
1) Dr. Standley’s website. (2000-2013). http://www.drstandley.com/bodysystems_respiratory.shtml
2) Mechanics of Breathing Website. (n.d.). http://www.breath2000.org/physiology.html
3) The Science of Breathing website. (n.d.). http://www.unm.edu/~lkravitz/Article%20folder/Breathing.html
4) The Physics of the Human Body website. (2002). http://mspde.usc.edu/inspiring/resource/western%20medicine/body_manu.pdf
5) Medical Physiology website. (n.d.). https://www.inkling.com/read/medical-physiology-rodney-rhoades-david-bell-4th/chapter-18/pulmonary-pressures-and-airflow
Books:
1) James, R. (1998). The human body. Hauppauge, NY: Barron's Educational Series.
2) Ji, Z., Yu, E., & Tang, J. (2007). Our body: The universe within. [Towson, MD]: The Universe Within Touring.
Video:
1) The Respiratory System. (2010, May 5). YouTube. Retrieved November 29, 2013, from https://www.youtube.com/watch?v=hc1YtXc_84A
Pictures:
1) Stock Photo - 3d rendered, medical illustration of the human respiratory system website. (n.d.). http://www.123rf.com/photo_12845352_3d-rendered-medical-illustration-of-the-human-respiratory-system.html
2) The Respiratory System website. (n.d.). http://www.energyeducation.tx.gov/environment/section_4/topics/the_respiratory_system.html
3) The Respiration Connection website. (n.d.). http://saveyourself.ca/articles/respiration-connection.php
