The lungs work hard to provide oxygen to our body. As we inhale, it expands much like a balloon with fresh, oxygen-rich air. When we exhale, it shrivels up, releasing air full of carbon dioxide, a waste product of our body’s natural functions.
The lungs are the primary organ of the respiratory system, the system responsible for us breathing properly. Remember that we breathe in through our nose. This air goes through several passageways – down the throat, voice box and windpipe – leading to the trachea.
The trachea branches into the primary bronchi on the left and right sides; one connected to each lung. They split further into many secondary and tertiary bronchi, becoming smaller and smaller, and eventually end into alveoli.
Alveoli are the basic unit of the lungs. These units are little air sacs where air ends up. Gas is exchanged here, as blood is refilled of oxygen and removed of its CO2 wastes. The air is then exhaled.
To protect against friction and damage, the lungs are surrounded by two slippery layers of tissue called pleura, which are filled with sticky pleural fluid. The pleura also help us breathe safely and normally.
This human lungs diagram labelling quiz can be a helpful study aid in reviewing the structure and composition of the lungs, and how air is inhaled, used to exchange gases, and exhaled.