Respiratory cycle is the process of which a person takes one breath .
Air enters our body either through the nose or your mouth.Then passes down the throat (pharynx) and through the voice box, or larynx.
As it travels, the air is humidified, filtered, and warmed.
The windpipe (trachea) is the largest airway.The trachea branches lead the air to the two lungs.
The alveoli are the areas within the lungs where the oxygen is transferred into the blood in exchange for carbon dioxide.