An impoant non-respiratory function of lungs is
These nonrespiratory functions of the lung include its own defense against inspired paiculate matter, the storage and filtration of blood for the systemic circulation, the handling of vasoactive substances in the blood, and the formation and release of substances used in the alveoli or circulation Ref: guyton and hall textbook of medical physiology 12 edition
Anion balance
Defence against inhaled air
Potassium balance
Calcium balance
Respiratory system