What can interrupt gas exchange in the lungs?

Gas exchange in the lungs primarily occurs in the alveoli, where oxygen is transferred to the blood, and carbon dioxide is removed. Constricted bronchioles can hinder airflow, but they do not directly impact the gas exchange process itself as effectively as the situation described in the selected answer.

In the case of low oxygen levels in the outside air, a significant reduction in the ambient oxygen concentration directly impacts the partial pressure of oxygen available for diffusion. When oxygen levels are low, the concentration gradient that allows oxygen to move from the alveoli into the bloodstream is diminished. This leads to less oxygen being available for the body’s tissues, effectively interrupting the gas exchange process.

Although increased blood flow typically facilitates better gas exchange by delivering more blood to the lungs for oxygenation, and excessive oxygen concentration could enhance the exchange process, they do not fundamentally alter the mechanics of gas exchange like low external oxygen levels can. Therefore, low oxygen levels in the outside air is the most direct and impactful factor that can interrupt the essential process of gas exchange in the lungs.