Why do we Need Oxygen?
One of the best ways to learn about a human being’s need for oxygen is to take a close look at what would happen without it. We need food, which our bodies transform into the energy we need. We need water, which we need to keep our bodies healthy and our blood flowing. We need oxygen because, without it, the rest of our systems wouldn’t operate at all.
Of the three – food, water and oxygen – we would die more quickly without oxygen than without the other two. Oxygen is inhaled into the lungs and enters our blood through alveoli. The oxygen is carried to the rest of the body through the blood. The oxygen is used to make water molecules. Water makes up the vast majority of our body tissue. In addition, nearly every function that keeps us alive uses oxygen as the source of energy. Oxygen is the prime ingredient for our body’s metabolism, the process that changes food into the fuel we need to continue living.
Since human beings are animals that live on land, we can get the oxygen we need from the air around us. The final product of our breathing is carbon dioxide, which we breath out (expel) into the atmosphere. Plants use carbon dioxide much as we use oxygen but plants add oxygen to the air. A healthy climate for human breathing includes healthy plants.
We mentioned learning about why we need oxygen by finding out what would happen without it. Human beings cannot survive for long periods of time underwater without mechanical breathing apparatus. A fish can because it has gills that take oxygen from the water around it. Our lungs can’t do that. Whether we breathe naturally or with help from scuba gear underwater, the pressure of the oxygen has to be correct.
We could breathe through a tube that reaches above the surface of the water. Men have done this with hollow plant stems and other devices when hiding from pursuers. The snorkel works on this premise as well. The amount of oxygen in the air around us is at the correct level for us to breathe it without major difficulty. Not only that, the normal air pressure is right for us as well. If the air pressure (per square inch) was too high animals wouldn’t survive. The same would be true if the pressure is too low.
If we are underwater and have a mechanical means of breathing, the oxygen stored in the tanks is highly compressed. It would be dangerous to try to breathe this directly into the lungs. The regulator valve at the top of the tank lowers the pressure to a safe range for us to breathe. The human body is a complex mix of various chemicals. Oxygen is just one of them, but it may be the more important.