noun
respiratory system
Anatomical term referring to the organs and structures involved in breathing, such as the lungs, trachea, and bronchi.
呼吸器系の病気には気管支炎や肺炎がある。
Diseases of the respiratory system include bronchitis and pneumonia.
呼吸器 refers to the respiratory organs themselves, while 呼吸器系 refers to the entire respiratory system as a functional unit.
Compound of 呼吸 (breathing) + 器 (organ) + 系 (system).