Question

What is the normal percentage of composition of gases in the inspired air and expired air respectively?

Answer 1

Hint: The movement of air into and out of the lungs that help in gaseous exchange by the human body is known as breathing. The most important function of the process is to take in the oxygen required for respiration and give out the carbon dioxide which is produced as a waste product.

Complete answer: The inspired air has the same composition of gases, as present in the atmosphere that is 78.08% nitrogen, 20.95% oxygen, and very small amounts of carbon dioxide, argon, hydrogen, helium, and neon. The oxygen from the inhaled gas is utilized by the cells in the body after reaching the lungs. If the inspired air contains more than an adequate quantity of nitrogen, it may result in discomforts such as fatigue, headache, and nausea. The air exhaled is made up of about 5% of carbon dioxide, which is formed as the waste product of cellular respiration, and after it being released from the lungs, it is exhaled out into the atmosphere. The exhaled amount of air is always greater than the inhaled amount of air. Besides these, the air can contain minute quantities of water vapor.

Note: Under certain special circumstances, such as in the case of deep-sea diving, the cylinder filled with oxygen gas, is diluted with minute quantities of helium gas. The mixture made of these gases has less resistance than oxygen gas alone. Thus, the divers would experience less strain in inhaling. This composition is known as heliox. The combination of oxygen, helium, and nitrogen is known as trimix.