500
Starting with the trachea, the anatomical pathway to the alveoli is as follows: trachea, __________, lobar bronchi, _________, __________, _________, respiratory bronchioles, ____________, __________, alveoli. The left lung has _________ lobar bronchi and the right lung has __________ lobar bronchi.
Main bronchi, segmental bronchi, bronchioles, terminal bronchioles, alviolar ducts, alciolar sacs, 2, 3.