Our respiratory organs comprise of the nose, mouth, windpipe, bronchi and lungs. When we inhale, the air follows precisely this path. The air is warmed and moistened in the nose, and undergoes coarse cleaning by tiny hairs on the nasal mucosa. When you inhale through your mouth, the air is not moistened and reaches the windpipe without having been cleaned. That’s why it is always better to breathe through your nose.
The air flows through the windpipe into the bronchi. The windpipe and the bronchi are lined with a countless number of extremely fine cilia (microscopic hairs), which are in perpetual movement in the direction of the throat. This serves to expel small foreign objects and mucus.
The term “bronchi” refers to the passage from the windpipe to the lungs. At the end of the windpipe, the channels of the bronchi separate and form a system of fine tubes with numerous treelike branches. These extremely fine branches transition into the alveoli. The lungs comprise more than 300 million of these tiny alveolar sacs, which are surrounded by a thick network of extremely small blood vessels. This is where the oxygen from the air is exchanged with the carbon dioxide which is formed in the body.