Pleura

Definition

The pleura is a thin, double-layered membrane that surrounds the lungs and lines the inside of the chest cavity. It plays a crucial role in the functioning of the lower respiratory system.

5 Must Know Facts For Your Next Test

1. The pleura produces a small amount of lubricating fluid that allows the visceral and parietal layers to slide smoothly against each other during breathing.
2. The pleural cavity is a potential space that normally contains only a thin layer of pleural fluid, allowing the lungs to expand and contract during respiration.
3. The parietal pleura is innervated and can sense pain, while the visceral pleura is not innervated and cannot directly feel pain.
4. Pleural effusions, or the abnormal accumulation of fluid in the pleural cavity, can impair lung function and lead to respiratory distress.
5. Inflammation of the pleura, known as pleurisy, can cause sharp chest pain that worsens with breathing or coughing.

Review Questions

• Describe the role of the pleura in the lower respiratory system.
  • The pleura plays a crucial role in the lower respiratory system by surrounding the lungs and lining the inside of the chest cavity. The visceral pleura covers the surface of the lungs, while the parietal pleura lines the chest wall. The pleural cavity between these two layers contains a small amount of lubricating fluid that allows the lungs to expand and contract smoothly during breathing. The pleura's structure and function are essential for normal respiratory mechanics and gas exchange in the lungs.
• Explain the differences between the visceral and parietal pleura and how they contribute to respiratory function.
  • The visceral pleura is the inner layer that directly covers the surface of the lungs, while the parietal pleura is the outer layer that lines the inside of the chest cavity. The visceral pleura is not innervated and cannot directly feel pain, whereas the parietal pleura is innervated and can sense pain. The pleural cavity between these two layers contains a small amount of lubricating fluid that allows the lungs to slide smoothly against the chest wall during breathing. This interaction between the visceral and parietal pleura is essential for normal respiratory mechanics and gas exchange in the lower respiratory system.
• Analyze the potential consequences of abnormal pleural conditions, such as pleural effusions or pleurisy, on respiratory function.
  • Abnormal conditions affecting the pleura can significantly impair respiratory function. Pleural effusions, or the abnormal accumulation of fluid in the pleural cavity, can restrict lung expansion and reduce the efficiency of gas exchange. This can lead to respiratory distress and impaired oxygen delivery to the body's tissues. Pleurisy, or inflammation of the pleura, can cause sharp chest pain that worsens with breathing or coughing, further compromising respiratory mechanics and overall respiratory function. These pleural conditions highlight the critical role of the pleura in facilitating normal, unimpeded breathing and the importance of maintaining the integrity of this structure for optimal lower respiratory system performance.

Related terms

Visceral Pleura: The inner layer of the pleura that directly covers the surface of the lungs.

Parietal Pleura: The outer layer of the pleura that lines the inside of the chest cavity.

Pleural Cavity: The space between the visceral and parietal pleura, filled with a small amount of pleural fluid.