Trachea Prima bronchus 导气部: Secondary 小气管 small bronchus Right lung 细支气管 bronchiole Left lung Conducting portion 终未细支气管t terminal bronchiole bronchiole(1 mm or less in diameter) 呼吸部: Terminal bronchiole 呼吸性细支气管 Respiratory 肺泡管 alveolar duct Alveolar duct Respiratory portion 肺泡囊 alveolar sac 肺泡 alveoli Alveolar sac (termination of alveolar duct)导气部： 呼吸部： 小气管small bronchus 细支气管bronchiole 终末细支气管terminal bronchiole 呼吸性细支气管respiratory ～ 肺泡管 alveolar duct 肺泡囊 alveolar sac 肺泡 alveoli