Question

Which of the of the following is FALSE in regard to obstructive disorders? A. Results from limitation of airflow due to partial or complete obstruction B. Causes a reduced expansion of lung parenchyma resulting in decreased TLC C. Causes air to remain trapped inside the lung after full expiration D. Results in a FEV₁ /FVC ratio is below 80%

Answer 1

The false statement regarding obstructive disorders is that they cause a reduced expansion of lung parenchyma resulting in decreased TLC. This is a characteristic of restrictive, not obstructive, lung diseases. Obstructive diseases are marked by airway obstruction, air trapping, and a reduced FEV1/FVC ratio.

Step-by-step explanation:

The statement that is FALSE regarding obstructive disorders is: B. Causes a reduced expansion of lung parenchyma resulting in decreased TLC. Obstructive lung diseases, such as emphysema, asthma, and pulmonary edema, are characterized by obstruction to airflow due to narrowing or blockage of the airways. This results in air becoming trapped in the lungs after full expiration, not necessarily reducing the expansion of lung parenchyma. In contrast, restrictive lung diseases, such as pulmonary fibrosis or respiratory distress syndrome, lead to reduced expansion of lung tissue, which is what reduces the total lung capacity (TLC).

In obstructive diseases, the FEV₁/FVC ratio is often below 70%, not necessarily below 80% — making choice D incorrect. A low FEV₁/FVC ratio indicates that there is significant obstruction to air flow out of the lungs. Therefore, while C is a true statement about obstructive diseases, the false statement in regard to obstructive disorders is option B.