Oxygen; Some Medical Facts

We need to breathe in air containing oxygen in order to survive and to supply energy to our bodies. After we have breathed in air, the oxygen in this air combines with the hemoglobin of the blood to form a compound called oxyhemoglobin. This oxyhemoglobin is carried by the blood to tissues where oxygen is released. This released oxygen then reacts with the food and waste products in the cells, producing energy and carbon dioxide. The carbon dioxide is carried back to the lungs and is exhaled.

How do we know that we need to breathe in air? Is it because our body tells us there is too little oxygen? No. Our body gets the information from the amount of carbon dioxide that has been dissolved in the blood. If a lot of carbon dioxide has been dissolved we feel the need to breathe. In fact, it has been reported that people who are breathing in only nitrogen do not know that they are suffocating. This is because there is no carbon dioxide to tell them they need to breathe air. It is the carbon dioxide that stimulates the respiratory centre of the brain making the person breathe faster.

Oxygen can cause spontaneous combustion of certain materials. Oxygen combines slowly with iron, oil, and so on, causing heat, but usually there is sufficient ventilation to keep the temperature  low and combustion cannot take place. For combustion to take place three things are needed: Sufficient heat, oxygen and a fuel. When there is little ventilation, heat is not carried away and builds up. Oily rags that are not properly ventilated can heat up more and more until the temperature is sufficient for burning (spontaneous combustion takes place). Containers having oily rags in must therefore be sealed properly so there is not sufficient oxygen to cause combustion, or they could be hung up where there is good ventilation so that heat is taken away.

Oxygen is often used in the operating room. For this reason nylon clothing may be forbidden (nylon causes sparks) because of the danger of fire. Electrical devices are also excluded because of the danger of fire.

“Chemistry for the health sciences” by Sackheim and Schultz says: “Formerly, all premature infants were routinely given oxygen until respiratory sufficiency had been established. Now it is known that when the concentration of oxygen rises above 40 per cent in the inspired air, premature infants develop retrolental fibroplasia, a disease that  affects the eyes. This disease produces complete or nearly complete blindness…”

If anyone needs to use oxygen it should be used with care.