How Lungs Work
Lungs are vital organs enabling us to breathe, bringing oxygen into our bodies and removing carbon dioxide. This gas exchange sustains life.
The process begins with inhalation (breathing in). The diaphragm, a dome-shaped muscle, contracts and flattens, expanding the chest cavity. This creates lower pressure in the lungs, drawing air inward through the airways. As stated by the National Heart, Lung, and Blood Institute (NHLBI) https://www.nhlbi.nih.gov/health/lungs, "When you inhale (breathe in), air enters your lungs, and oxygen from that air moves to your blood." Simultaneously, carbon dioxide, a waste product, moves from the blood into the lungs.
Exhalation (breathing out) is a passive process. The diaphragm relaxes, returning to its dome shape, reducing the chest cavity's volume. This increases pressure in the lungs, forcing air—carrying carbon dioxide—outward.
Oxygen and Carbon Dioxide Exchange
Air entering the lungs reaches tiny air sacs called alveoli. These alveoli are surrounded by capillaries, tiny blood vessels. The thin walls of both alveoli and capillaries allow for efficient gas exchange: oxygen from the inhaled air passes into the blood, while carbon dioxide from the blood diffuses into the alveoli to be expelled. As noted by Temple Health https://www.templehealth.org/services/lung/patient-care/patient-resources/understanding-lung-disease/how-lungs-work, "The lungs are responsible for removing carbon dioxide from the blood and adding oxygen to it." This exchange is facilitated by the close proximity and thin membranes of the alveoli and capillaries. The heart and lungs work together to achieve this crucial gas exchange.
The Role of Airways
Airways, including the trachea (windpipe) and bronchi, carry air to and from the alveoli. The American Lung Association highlights the diaphragm's role in breathing, stating that it "does most of the breathing work by expanding and contracting the chest to draw air in and out of your lungs" https://www.lung.org/lung-health-diseases/how-lungs-work. This efficient system ensures that every part of the body receives the oxygen it needs for survival, as explained by the Lung Foundation Australia https://lungfoundation.com.au/lung-health/protecting-your-lungs/how-your-lungs-work/.
