How Our Lungs Work: From Breath to Blood

    A human can spend 3 weeks without food, 3 days without water and less than 3 minutes without air. Thanks to the work of our lungs we have the ability to breathe. Breathing is fundamental to any human, but why exactly is that?

    When we breathe the air travels from the outside environment into our body. Firstly the air passes through  the nose or mouth, which represent entry ways, and then travels to the throat (pharynx). After passing through the pharynx the air continues traveling deeper into our body past the voice box (larynx) and through the windpipe (trachea). The trachea splits into the left and right bronchi (one for each lung). Each bronchus divides into narrower and narrower airways within the lungs. Our lungs are located on both sides of the breast bone within the chest cavity. They are separated into five lobes and they contain small balloons called "alveoli". The alveoli come from the bronchi. As the trachea splits into bronchi, similar to a tree, the bronchi begins spreading and "branching out" into narrower and narrower pathways until eventually they become alveoli. Our body contains around 300 million alveoli and they have the responsibility of one of the most vital processes in our body, the gas exchange.

    As mentioned, the alveoli are small balloons within the lungs that help with the gas exchange, but what exactly is that? The gas exchange within our body happens in the alveoli. As its name says it is a process of exchanging gas, more specifically oxygen and carbon dioxide. Through the body's several metabolic and catabolic processes our body creates carbon dioxide as a useless byproduct. This carbon dioxide travels from all the cells in our body to the lungs through our blood. Our blood contains hemoglobin and this substance helps with binding carbon dioxide with the red blood cells. Then our blood travels through the body's cardiovascular system all the way to the lungs. The alveoli don't just represent small balloons, in fact they are covered with hundreds of tiny capillaries and this is where the gas exchange happens. When the blood rich in carbon dioxide reaches the alveoli, the carbon dioxide gets released into the small alveoli through a process known as diffusion. The same applies to oxygen. Through diffusion the oxygen travels from the alveoli to the capillaries around it. When it enters the capillaries it binds to the hemoglobin of the red blood cells and then travels through our body.

    In conclusion, our body is truly fascinating and amazing. Our red blood cells can take just one minute to travel the body's entire circulatory system and back to the lungs for oxygen. Oxygen is essential to the body because it is essential when it comes to creating energy for our body. It is part of all the catabolic and anabolic processes in our body. Simply put, without oxygen our body would have no energy, and without energy our body could not do any of its vital processes. 

Sources:

1. https://my.clevelandclinic.org/health/body/8960-lungs
2. https://www.lung.org/lung-health-diseases/how-lungs-work
3. https://www.templehealth.org/services/lung/patient-care/patient-resources/understanding-lung-disease/how-lungs-work
4. https://www.lung.ca/lung-health/how-your-lungs-work/how-your-lungs-work
5. https://theconversation.com/your-lungs-are-really-amazing-an-anatomy-professor-explains-why-106669
6. https://www.nhlbi.nih.gov/health/lungs/breathing-benefits