The lungs work by facilitating the exchange of gases-oxygen and carbon dioxide-between the air we breathe and the bloodstream, a process essential for life.
How the Lungs Work
- Breathing In (Inhalation): When you inhale, air enters through your nose or mouth, travels down the throat (pharynx), passes the voice box (larynx), and moves into the windpipe (trachea). The trachea splits into two bronchial tubes, each leading to one lung. These tubes branch into smaller tubes called bronchioles, which end in tiny air sacs called alveoli
- Gas Exchange in Alveoli: The alveoli are surrounded by tiny blood vessels called capillaries. Oxygen from the inhaled air passes through the thin walls of the alveoli into the blood in the capillaries by diffusion. At the same time, carbon dioxide, a waste gas produced by the body's cells, moves from the blood into the alveoli to be exhaled
- Transporting Oxygen: The oxygen-rich blood is carried from the lungs to the heart, which pumps it through arteries to all body tissues and cells. Cells use oxygen to produce energy and generate carbon dioxide as a waste product
- Breathing Out (Exhalation): The carbon dioxide-rich blood returns to the lungs via veins. Carbon dioxide passes from the blood into the alveoli and is expelled from the body when you exhale
Role of Muscles and Structures
- The diaphragm , a dome-shaped muscle beneath the lungs, contracts and moves downward during inhalation, expanding the chest cavity and pulling air into the lungs. When it relaxes, it moves upward, pushing air out
- The ribs also move slightly to help expand and contract the chest cavity
Defense Mechanisms
- The bronchial tubes are lined with cilia (tiny hair-like structures) and coated with mucus that trap dust, germs, and other particles. The cilia move the mucus upward toward the throat, where it can be coughed out or swallowed, helping keep the lungs clean
This continuous cycle of breathing in oxygen and breathing out carbon dioxide keeps the body's cells supplied with the oxygen they need to function and removes waste gases efficiently
When you can't breathe, nothing else matters. - This highlights the vital role of the lungs in sustaining life
