The Diaphragm's Role in Breathing
Inhalation and exhalation are the processes by which the body brings in oxygen and expels carbon dioxide. The breathing process is aided by a large dome-shaped muscle under the lungs called the diaphragm.
When you breathe in, the diaphragm contracts downward, creating a vacuum that causes a rush of fresh air into the lungs.
The opposite occurs with exhalation, where the diaphragm relaxes upwards, pushing on the lungs, allowing them to deflate.
Clearing the Air
The respiratory system has built-in methods to prevent harmful substances in the air from entering the lungs.Small hairs in your nose, called cilia, help filter out large particles. Cilia are also found along your air passages and move in a sweeping motion to keep the air passages clean. But if harmful substances, such as cigarette smoke, are inhaled, the cilia stop functioning properly, causing health problems like bronchitis.
Mucus produced by cells in the trachea and bronchial tubes keeps air passages moist and aids in stopping dust, bacteria and viruses, allergy-causing substances, and other substances from entering the lungs.
Impurities that do reach the deeper parts of the lungs can be moved up via mucous and coughed out or swallowed.if