What can be the non-respiratory functions of lungs:
NON respiratory function of lung: 

ACE synthesized by lung – Na balance. 
Fibrinolytic function – Pulmonary Endothelium is rich in PLASMIN activator. 
Heparin – Lung is rich in mast cells which secrete heparin. 
SURFACTANT – Synthesized by type 2 alveolar epithelial cells.
Sodium balance.
Fibrinolytic function.
Secretion of heparin.
All of the above.