 Osmoregulation: the control of osmotic pressure within cells and simple organisms, by which maintain a balance between the fluid inside them and that outside their environment  Excretion: the passing of the waste products of metabolism such as faeces, urine, sweat or carbon dioxide out of the body

 is to carry oxygen into the body, while removing carbon dioxide.  is to maintain the body's respiration system, which means that the lungs bring oxygen to the bloodstream via alveoli, or tiny sacs in the lungs.

 The lungs of organisms constantly secrete gaseous wastes from the bloodstream as a regular part of respiration. 

Lungs supply oxygen to your blood and they also clear waste carbon dioxide. If they stop working your blood loses oxygen and starts to build up an excess of waste carbon dioxide. Muscles and other tissue can survive quite a long period without oxygen, but the brain cannot. Shortage of oxygen to the brain will cause you to lose consciousness. If the oxygen supply is not rapidly restored you can suffer brain damage. If at this stage oxygen supply is restored you can live, though you may have serious problems for many years. If the oxygen supply is still not restored your brain will stop functioning, though the rest of your body can survive. If at this stage oxygen supply is restored you become a coma patient with little chance or reviving. And obviously if oxygen supply is never restored, you die. This can be caused by: Smoking over a long period of time