What factor can cause CO2 exchange to become diffusion limited?

What factor can cause CO2 exchange to become diffusion limited?

• A. Dehydration
• B. Elevation
• C. Exercise
• D. Nutrition

Answer: (C)

CO2 exchange can become diffusion limited when there is an increase in the demand for gas exchange that outpaces the ability of the respiratory system to facilitate that exchange. During exercise, the body’s metabolic rate significantly increases, leading to a greater production of carbon dioxide as a byproduct of enhanced muscular activity. This increased level of CO2 must be efficiently removed from the bloodstream to maintain homeostasis and prevent respiratory acidosis. Under normal resting conditions, the diffusion of CO2 from areas of high concentration in the tissues to areas of lower concentration in the alveoli is typically adequate. However, during exercise, the demand for oxygen and the production of CO2 can elevate to such a degree that the body's ventilation may not sufficiently increase to accommodate the rapid changes in gas concentrations, leading to a situation where the diffusion of CO2 is restricted by the rate of blood flow and the efficiency of gas exchange in the lungs, rather than the concentration gradient itself. Factors like dehydration, elevation, and nutrition influence various aspects of physical performance and respiratory function, but they do not directly contribute to the mechanism of diffusion limitation in CO2 exchange in the same way that the increased metabolic demands during exercise do. Thus, the condition of exercise, with its raised carbon dioxide production and the need

CO2 exchange can become diffusion limited when there is an increase in the demand for gas exchange that outpaces the ability of the respiratory system to facilitate that exchange. During exercise, the body’s metabolic rate significantly increases, leading to a greater production of carbon dioxide as a byproduct of enhanced muscular activity. This increased level of CO2 must be efficiently removed from the bloodstream to maintain homeostasis and prevent respiratory acidosis.

Under normal resting conditions, the diffusion of CO2 from areas of high concentration in the tissues to areas of lower concentration in the alveoli is typically adequate. However, during exercise, the demand for oxygen and the production of CO2 can elevate to such a degree that the body's ventilation may not sufficiently increase to accommodate the rapid changes in gas concentrations, leading to a situation where the diffusion of CO2 is restricted by the rate of blood flow and the efficiency of gas exchange in the lungs, rather than the concentration gradient itself.

Factors like dehydration, elevation, and nutrition influence various aspects of physical performance and respiratory function, but they do not directly contribute to the mechanism of diffusion limitation in CO2 exchange in the same way that the increased metabolic demands during exercise do. Thus, the condition of exercise, with its raised carbon dioxide production and the need