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.
Using these words and information we can now summarise osmosis with its definition. Osmosis is the movement of water molecules through a selectively permeable membrane from higher water concentration to a lower water concentration-or-down a concentration gradient. Animal cells are surrounded only by the membrane and may swell up and burst if too much water enters by osmosis.