What is the primary gas exchanged in the lungs during respiration?

The primary gas exchanged in the lungs during respiration is carbon dioxide. During the process of respiration, the body takes in oxygen from the atmosphere and delivers it to the bloodstream for use by the cells. This oxygen is essential for cellular metabolism. As cells use oxygen to produce energy, they generate carbon dioxide as a waste product.

This carbon dioxide is transported back to the lungs via the bloodstream, where it is expelled from the body when we exhale. Therefore, carbon dioxide plays a critical role in maintaining the body's acid-base balance and is the main gas that is exchanged in the lungs, ensuring that levels of oxygen and carbon dioxide remain optimal for physiological functions.

Ozone, nitrogen, and hydrogen do not play a significant role in this respiratory exchange. Ozone is not used by the body in the same manner as oxygen and can actually be harmful at ground level. Nitrogen, while present in the atmosphere, is largely inert and does not participate in metabolic processes in the same way oxygen and carbon dioxide do. Hydrogen gas is not a naturally occurring gas for respiration in the human body and is not exchanged in the lungs like oxygen and carbon dioxide.