Our survival depends on oxygen. Oxygen is one of the most vital elements, the lack of which is immediately felt by us. Not just humans but all other animals, birds, amphibians and fishes also need oxygen for their survival. The most vital function of oxygen is that it provides us with energy. The food we eat gets digested in our stomach. After digestion the food transforms into simpler substances from complex compounds. The digested food then is transported to each of our body cells. But without oxygen the food that reaches our body cell will be useless.
Mankind breathes in oxygen through the nostrils. The oxygen is transported to the body cells through the blood vessels. At the lungs the oxygen gets into the blood vessels and then they are carried off by the hemoglobin present in RBCs. When the oxygen molecules reach the body cells the process of breaking the food particles get started. In the presence of the oxygen molecules the food gets broken into energy and this energy is used to maintain our internal organs and helps us in our work. Without oxygen we will not get energy for working. Whenever there is a lack of oxygen we start feeling drowsy and tired.
A gaseous exchange occurs in our lungs. Oxygen gets inside the blood vessels and at the same time carbon dioxide gets out of our body through the channel of lungs, nasal passage and nostrils. This carbon dioxide is removed from the body cells by the blood. Without oxygen the whole process would not be complete. Only by drawing in oxygen, we can remove carbon dioxide from our body. Respiration is the process that helps in this matter. Without oxygen our body organs will not function appropriately and the cells too will stop working.
