The air enters the lungs through the nose and mouth, initially passing through the pharynx, from there the air passes through the epiglottis to reach the larynx (where the vocal cords meet); then continue to the trachea, which is divided into 2 tubes in its lower part, called right and left bronchial (primary bronchi). It ends up in even smaller tubes called bronchioles, as thin as a hair and finally ending, in the alveoli, where the gas exchange occurs.
