The percentage inhaled is roughly 79% but it is only 74% when exhaled. The volume of Nitrogen does not change but the percentage out of all the exhaled gas decreases as there is far more CO2 and Water Vapour. Nitrogen itself not actually used up by the body, it is simply a byproduct of the nitrates and various emissions involved in photosynthesis from plants and various algae that get pumped with whimsical abandon into the atmosphere. Typical trees. Lest not forget the delicate equilibrium between humans and plants.
Nitrogen is a gas that is present in the same concentration in inhaled and exhaled air, as it is not chemically changed by the body during respiration.
Biological value
Nitrogen is not used by the body; oxygen is taken in and carbon dioxide and water goes out.
Exhaled air, which has a slightly higher amount of carbon dioxide, is heavier than inhaled air.
Inhaled air contains a greater volume of oxygen than carbon dioxide. Exhaled air is the opposite, since after the exchange of gases in the lungs the carbon dioxide in the blood is transferred into the lungs. Exhaled air contains a greater volume of carbon dioxide than oxygen. Also, there is more water vapour in exhaled air than inhaled air.
Breathing.
Nitrogen is the most abundant gas in the atmosphere ( ~ 80% ) and therefore is the dominant species in both inspired as well as expired air.
Because the body has used the oxygen in the air to oxidize the nutrients you eat, this process combines the oxygen that you inhaled with carbon which makes up part of the nutrients you eat to form a poisonous gas "carbon-dioxide" which is then transported back to the lungs and exhaled along with moisture.
Exhaled air has less oxygen than inhaled air.Exhaled air has more carbon dioxide than inhaled air.Exhaled air is warmer that inhaled air.Maybe the first 2 are redundant, but I think that should work!
Exhaled air contains CO2 (Carbon Dioxide) and Inhaled air contains O2(Oxygen).
Carbon dioxide is exhaled more than it is inhaled, as it is a waste product of metabolism. Nitrogen is also exhaled more than it is inhaled because it makes up a large percentage of the air we breathe, but is not used by our bodies.
On average, humans breathe out about 3.5% of nitrogen in exhaled air, which is roughly 78% of the air we breathe in. This nitrogen is not utilized by the body and is simply exhaled back into the atmosphere.