Bronchial tree-, mucous membrane-lined tubular airways,microscopic air sacs of their lungs called alveoli Primary bronchi: first branches, off the trachea, leads to a lung
Secondary bronchi:main bronchi, enters a lobe of a lung
Tertiary bronchi: lobar bronchi, enters a
the segment of a lung
Bronchioles: small tubular organs branch off segmental bronchi
Alveoli: consist of simple squamous epithelium, extensive capillary
networks, gas exchange b/w the air and blood,
Alveolar sacs: off alveolar ducts, air sacs called alveoli
Alveolar ducts: off respiratory bronchioles
Respiratory bronchioles: off terminal bronchioles,
alveoli,gas exchange
Terminal bronchioles: off larger bronchioles, small
bronchioles, without gas exchange