What is the primary composition of inhaled air?

The primary composition of inhaled air is characterized by a high concentration of oxygen (O2) and a low concentration of carbon dioxide (CO2). In the atmosphere, inhaled air consists of approximately 21% oxygen and about 0.04% carbon dioxide, making the availability of oxygen significantly higher compared to carbon dioxide. This oxygen is essential for the process of respiration, where cells use it to produce energy via aerobic metabolism.

While nitrogen is present in the atmosphere at about 78%, its role in respiration is minimal since it does not participate in the metabolic processes of the body. The ventilation process effectively draws in this mixture, but the critical component for bodily function remains the high oxygen content. Hence, inhaled air is primarily composed of high oxygen and low carbon dioxide.