Which response accurately describes the relationship between arterial oxygen levels and carbon dioxide transport?

The response that states diffusion of CO2 occurs concurrently with oxygen transport is correct because it reflects the physiological principles of gas exchange in the lungs and tissues. In the alveoli, oxygen from the inspired air diffuses into the bloodstream while carbon dioxide, which is a waste product of cellular metabolism, diffuses from the blood into the alveoli to be exhaled. This simultaneous process is fundamental to respiratory physiology.

In the lungs, oxygen binds to hemoglobin, while carbon dioxide is transported in various forms, primarily as bicarbonate ions. The efficiency of this gas exchange is influenced by several factors, including the partial pressures of both gases. The relationship is often described in terms of Henry's law and the Haldane effect, which asserts that high levels of oxygen increase the affinity of hemoglobin for oxygen while facilitating the release of carbon dioxide from the blood.

Therefore, understanding that these processes occur concurrently helps highlight the integrated nature of respiratory function, where oxygen and carbon dioxide transport are interconnected rather than isolated events.