Why a Chest Tube is Placed. A chest tube is placed for a variety of reasons. One reason, as you mentioned, is to help the lung re-inflate when someone has a collapsed lung, also known as a pneumothorax. In that circumstance, a chest tube is inserted along the side of the ribs to allow the lung to reinflate.
A. Osmosis is the passive movement of water from an area high in water concentration, across a semi-permeable membrane, to an area low in water concentration.
Passive transport of molecules A membrane can allow molecules to be passively transported through it in three ways: diffusion, osmosis, and filtration. Diffusion: Sometimes organisms need to move molecules from an area where they are highly concentrated to an area where the molecules are less concentrated.