Lungs are basically a sack of elastic tissue located below the rib cage and above the diaphragm. They are an important part of the respiratory system and assist in excretory waste management in the body. Breathing is one important part of the respiration which provides our bodies with a continuous supply of oxygen. Oxygen is the fuel of life which keeps us all alive. Oxygen enters our lungs as part of the air that we breathe. It goes to the blood vessels deep into our lungs and then spread towards all parts of our body. As our body uses oxygen, it makes a waste product called carbon dioxide. We get rid of carbon dioxide when we breathe out.