Lung Compliance

Definition

Lung compliance is a measure of the lung's ability to stretch and expand during inhalation. It is a key factor in determining the work required to breathe and the overall efficiency of the respiratory system.

5 Must Know Facts For Your Next Test

1. Lung compliance is inversely related to the stiffness of the lungs, with more compliant lungs requiring less pressure to expand.
2. Decreased lung compliance, as seen in conditions like pulmonary fibrosis, increases the work of breathing and can lead to respiratory fatigue.
3. Surfactant production is a critical factor in maintaining normal lung compliance, as it reduces surface tension within the alveoli.
4. Lung compliance can be affected by changes in lung volume, with lower volumes typically resulting in decreased compliance.
5. Measuring lung compliance is an important diagnostic tool for evaluating respiratory function and detecting lung disorders.

Review Questions

• Explain how lung compliance is related to the work of breathing.
  • Lung compliance is inversely related to the work of breathing. Lungs with higher compliance require less pressure to expand during inhalation, reducing the overall work needed to ventilate the lungs. Conversely, decreased lung compliance, as seen in conditions like pulmonary fibrosis, increases the pressure required to inflate the lungs, resulting in greater work of breathing and potentially leading to respiratory fatigue.
• Describe the role of surfactant in maintaining normal lung compliance.
  • Surfactant, a substance produced by alveolar cells, is a critical factor in maintaining normal lung compliance. Surfactant reduces the surface tension within the alveoli, making it easier for the lungs to expand and stretch during inhalation. Without adequate surfactant production, the alveoli would be more prone to collapse, leading to decreased lung compliance and increased work of breathing. The regulation of surfactant levels is, therefore, a key mechanism by which the body maintains optimal lung compliance.
• Analyze how changes in lung volume can affect lung compliance, and explain the potential implications for respiratory function.
  • Lung compliance is influenced by changes in lung volume, with lower volumes typically resulting in decreased compliance. As the lungs become smaller, the alveolar walls are brought closer together, increasing the surface tension and making it more difficult for the lungs to expand. This decreased compliance increases the work required to inhale, potentially leading to respiratory fatigue and impaired gas exchange. Conversely, at higher lung volumes, compliance may also decrease due to the stretching and stiffening of the lung tissue. Understanding the relationship between lung volume and compliance is crucial for evaluating respiratory function and detecting lung disorders that may affect this delicate balance.

Related terms

Airway Resistance: The resistance to airflow through the airways, which affects the work of breathing and lung compliance.

Surfactant:

A substance produced by alveolar cells that reduces surface tension within the alveoli, improving lung compliance.

Elastic Recoil: The natural tendency of the lungs and chest wall to return to their resting position, which is influenced by lung compliance.