What causes the decrease in compliance associated with pulmonary fibrosis?

What causes the decrease in compliance associated with pulmonary fibrosis?

• A. Fluid accumulation
• B. Scar tissue around alveoli
• C. Airway obstruction
• D. Lung volume expansion

Answer: (B)

The decrease in compliance associated with pulmonary fibrosis is primarily caused by the scar tissue that forms around the alveoli. In pulmonary fibrosis, the lung tissue becomes damaged and inflamed, leading to the development of excessive fibrous connective tissue. This scarring stiffens the lung tissue, making it less elastic and reducing its ability to expand during inhalation. Consequently, the lung's compliance, or its capability to stretch and accommodate air, diminishes significantly. This leads to increased work of breathing and difficulty in gas exchange, as the stiffened lungs cannot properly expand and contract. The other options, while related to pulmonary conditions or mechanics, do not accurately describe the specific cause of decreased compliance in pulmonary fibrosis. For instance, fluid accumulation might impact lung function but is not a defining characteristic of pulmonary fibrosis. Airway obstruction pertains to issues with airflow as seen in conditions like asthma or chronic obstructive pulmonary disease (COPD), rather than the intrinsic lung tissue changes in fibrosis. Lung volume expansion, on the other hand, implies an increase in lung capacity, which contradicts the effects of fibrosis as it is associated with limited expansion due to scarred, rigid lung tissue.

The decrease in compliance associated with pulmonary fibrosis is primarily caused by the scar tissue that forms around the alveoli. In pulmonary fibrosis, the lung tissue becomes damaged and inflamed, leading to the development of excessive fibrous connective tissue. This scarring stiffens the lung tissue, making it less elastic and reducing its ability to expand during inhalation. Consequently, the lung's compliance, or its capability to stretch and accommodate air, diminishes significantly. This leads to increased work of breathing and difficulty in gas exchange, as the stiffened lungs cannot properly expand and contract.

The other options, while related to pulmonary conditions or mechanics, do not accurately describe the specific cause of decreased compliance in pulmonary fibrosis. For instance, fluid accumulation might impact lung function but is not a defining characteristic of pulmonary fibrosis. Airway obstruction pertains to issues with airflow as seen in conditions like asthma or chronic obstructive pulmonary disease (COPD), rather than the intrinsic lung tissue changes in fibrosis. Lung volume expansion, on the other hand, implies an increase in lung capacity, which contradicts the effects of fibrosis as it is associated with limited expansion due to scarred, rigid lung tissue.