What happens to compliance of lung tissue if the elastic fibers of the lung stroma are replaced with collagen fibers and scar tissue?
The correct answer and explanation is:
If the elastic fibers of the lung stroma are replaced with collagen fibers and scar tissue, the compliance of lung tissue decreases. Lung compliance refers to the ease with which the lungs can expand and contract during breathing. It is primarily determined by the amount of elastic fibers present in the lung tissue. These fibers allow the lungs to stretch and recoil, making it easier for air to flow in and out during respiration.
When the elastic fibers are replaced by collagen fibers, the tissue becomes stiffer. Collagen is less flexible and more rigid compared to elastin, the protein responsible for the lung’s elastic properties. Collagen fibers also form scar tissue, which further contributes to the stiffening of the lung tissue. As a result, the lungs lose their ability to expand and contract as efficiently, leading to reduced lung compliance.
This reduction in compliance can lead to impaired ventilation, meaning the lungs are less effective at taking in oxygen and expelling carbon dioxide. The decreased ability to expand means that the lungs may require more effort to inhale, leading to an increase in work of breathing. Additionally, this condition can lead to chronic respiratory problems, as seen in diseases like pulmonary fibrosis, where scar tissue formation impairs lung function over time.
In summary, replacing the elastic fibers with collagen fibers and scar tissue causes a decrease in lung compliance, making it harder for the lungs to expand. This results in increased respiratory effort, difficulty in breathing, and overall impaired lung function.