Which term describes the limit of gas exchange due to diffusion issues?

Which term describes the limit of gas exchange due to diffusion issues?

• A. Ventilation-perfusion mismatch
• B. Diffusion limitation
• C. Hypoventilation
• D. Obstructive lung disease

Answer: (B)

The term that describes the limit of gas exchange due to diffusion issues is diffusion limitation. This concept refers specifically to situations where the diffusion of gasses (such as oxygen and carbon dioxide) across the alveolar membrane is impaired, which can be due to various factors, such as increased thickness of the membrane or surface area reduction. In a healthy lung, gas exchange primarily depends on adequate ventilation (the flow of air) and perfusion (the flow of blood). However, if there's a problem with diffusion, even if ventilation and perfusion are functioning well, gas exchange can be impaired. This is typically seen in conditions that affect the alveolar-capillary interface, such as pulmonary fibrosis, where the increased thickness of the alveolar membrane limits gas diffusion. In contrast, ventilation-perfusion mismatch indicates an imbalance between the air reaching the alveoli and the blood flow in the surrounding capillaries, which is a different issue. Hypoventilation refers to inadequate ventilation and is primarily a problem of air flow rather than diffusion. Obstructive lung disease involves obstruction of airflow in the airways, affecting the ability to ventilate properly, but it doesn't specifically refer to issues with the diffusion of gases across the alveolar membranes. Each of these concepts relates to

The term that describes the limit of gas exchange due to diffusion issues is diffusion limitation. This concept refers specifically to situations where the diffusion of gasses (such as oxygen and carbon dioxide) across the alveolar membrane is impaired, which can be due to various factors, such as increased thickness of the membrane or surface area reduction. In a healthy lung, gas exchange primarily depends on adequate ventilation (the flow of air) and perfusion (the flow of blood). However, if there's a problem with diffusion, even if ventilation and perfusion are functioning well, gas exchange can be impaired. This is typically seen in conditions that affect the alveolar-capillary interface, such as pulmonary fibrosis, where the increased thickness of the alveolar membrane limits gas diffusion.

In contrast, ventilation-perfusion mismatch indicates an imbalance between the air reaching the alveoli and the blood flow in the surrounding capillaries, which is a different issue. Hypoventilation refers to inadequate ventilation and is primarily a problem of air flow rather than diffusion. Obstructive lung disease involves obstruction of airflow in the airways, affecting the ability to ventilate properly, but it doesn't specifically refer to issues with the diffusion of gases across the alveolar membranes. Each of these concepts relates to