ANATOMY and FUNcTion Upper respiratory tract nose, pharynx, larynx Lower respiratory tract trachea bronchi Right bronchus diverging at a lesser angle, foreign material more frequently aspirated Lobar, segmental, lobular a Terminal airways and alveoli respiratory bronchiole alveolar sac alveolus2 ANATOMY and FUNCTION ◼ Upper respiratory tract — nose, pharynx, larynx ◼ Lower respiratory tract — trachea & bronchi  Right bronchus diverging at a lesser angle, foreign material more frequently aspirated  Lobar, segmental, lobular ◼ Terminal airways and alveoli — respiratory bronchiole alveolar sac alveolus