Lungs

From Encyc

Lungs are organs used by animals for respiration. Gas is exchanged with the air: oxygen goes in and carbon dioxide goes out.

Upper airways are lined with mucus and cilia to remove debris and defend against infection.

Lungs can collapse.

Route[edit]

  • Trachea - windpipe
  • Bronchi
  • Bronchioles
  • Alveoli - tiny air-filled sacs with moist linings where gas exchange takes place
  • Surfactant prevents alveoli from collapsing due to surface tension of water. Premature babies sometimes lack surfactant.