Why do you breathe out the same amount of nitrogen you breath in?

Answer 1

Approximately 70% of the earth's atmosphere is nitrogen and around 14% is oxygen. The rest of our air is made of various trace elements and inert gases. Your question poses various interesting other questions, including the fact that decomposing animal bodies release primarily nitrogen. However, to go a little deeper, most of the nitrogen breathed in is expelled when you exhale. Very little is absorbed by the lungs, some of the nitrogen ends up absorbed by the liver and is passed out through urine, while a little more is exhaled after and entire circulation cycle. Build-up of too much nitrogen can cause various issues, anywhere from muscle cramps, hiccups, yawning and general fatigue. More interesting is the fact that while oxygen is absorbed from the inhalation, carbon dioxide is released. For most people without a deeper understanding, this would make no sense, because it would appear that the oxygen went no where and was not used at all. Again, this is not true. Only a fraction of oxygen inhaled is released. Approximately 8% of each exhale is CO2, while the rest is the un-used atmoshpere, again back to your nitrogen. Also, there's the question of where did the carbon come from to combine with the oxygen being exhaled. Our lungs and cells and blood stream perform a deep Ballet of combining, separating and re-mixing the elements of our atmosphere, taking only what we need and releasing the rest in a new form. Approximately 70% of the earth's atmosphere is nitrogen and around 14% is oxygen. The rest of our air is made of various trace elements and inert gases. Your question poses various interesting other questions, including the fact that decomposing animal bodies release primarily nitrogen. However, to go a little deeper, most of the nitrogen breathed in is expelled when you exhale. Very little is absorbed by the lungs, some of the nitrogen ends up absorbed by the liver and is passed out through urine, while a little more is exhaled after and entire circulation cycle. Build-up of too much nitrogen can cause various issues, anywhere from muscle cramps, hiccups, yawning and general fatigue. More interesting is the fact that while oxygen is absorbed from the inhalation, carbon dioxide is released. For most people without a deeper understanding, this would make no sense, because it would appear that the oxygen went no where and was not used at all. Again, this is not true. Only a fraction of oxygen inhaled is released. Approximately 8% of each exhale is CO2, while the rest is the un-used atmoshpere, again back to your nitrogen. Also, there's the question of where did the carbon come from to combine with the oxygen being exhaled. Our lungs and cells and blood stream perform a deep ballet of combining, separating and re-mixing the elements of our atmosphere, taking only what we need and releasing the rest in a new form.

Answer 2

Nitrogen is a biologically inert gas, so what you breathe in you eventually breathe back out unchanged. However some nitrogen dissolves in the bodily fluids (e.g. blood) and is absorbed by tissues, remaining in equilibrium with the gas in the atmosphere. Normally this dissolved/absorbed nitrogen presents no problem. However for people working under elevated pressure conditions like caisson workers or sea divers, they must be very careful in returning to normal pressure to let the extra dissolved/absorbed nitrogen be breathed out instead of forming bubbles and causing the bends.