The way we breathe
Breath enters the lungs through the nose, throat or pharynx, wind box or larynx (which consists of two vocal cords) and the trachea or windpipe. The windpipe branches into right and left bronchi and smaller bronchial tubes. These bronchial tubes sub divide into innumerable smaller tubes called bronchioles. The breath terminates in minute sub divisions in the small air sacs of the lungs. The lungs contain millions of air sacs.
The diaphragm induces air to be drawn into the lungs. When it expands, the size of the lungs increase, creating a vacuum inside. This forces the outside air to rush in. This is inhalation. Relaxation of the diaphragm forces air to be expelled from the lungs and chest, as they contract. This is exhalation.
