During which activity is CO2 exchange likely to become diffusion limited?

During which activity is CO2 exchange likely to become diffusion limited?

• A. Sleeping
• B. Eating
• C. Exercise
• D. Reading

Answer: (C)

CO2 exchange becoming diffusion limited during an activity depends on the balance between ventilation (the movement of air into and out of the lungs) and perfusion (the flow of blood to and from the lungs). During exercise, the body's demand for oxygen increases significantly, leading to an enhanced production of carbon dioxide as a metabolic byproduct. As exercise intensity increases, even though ventilation also increases to match the metabolic demands, the rapid changes in blood flow can sometimes surpass the body's ability to fully exchange CO2 and O2 through diffusion in the alveoli. This can result in conditions where the rate of CO2 production exceeds the rate at which it is removed from the bloodstream. In contrast, activities like sleeping, eating, or reading typically do not provide the same level of metabolic demand as exercise, allowing for more efficient gas exchange processes without the risk of diffusion limitations. Therefore, exercise is the activity most likely to push the body into a state where CO2 exchange may become diffusion limited.

CO2 exchange becoming diffusion limited during an activity depends on the balance between ventilation (the movement of air into and out of the lungs) and perfusion (the flow of blood to and from the lungs). During exercise, the body's demand for oxygen increases significantly, leading to an enhanced production of carbon dioxide as a metabolic byproduct.

As exercise intensity increases, even though ventilation also increases to match the metabolic demands, the rapid changes in blood flow can sometimes surpass the body's ability to fully exchange CO2 and O2 through diffusion in the alveoli. This can result in conditions where the rate of CO2 production exceeds the rate at which it is removed from the bloodstream.

In contrast, activities like sleeping, eating, or reading typically do not provide the same level of metabolic demand as exercise, allowing for more efficient gas exchange processes without the risk of diffusion limitations. Therefore, exercise is the activity most likely to push the body into a state where CO2 exchange may become diffusion limited.