Pleural Membrane

• The thorax is a sealed compartment lined by a thin, moist membrane called the pleural membrane.
• This membrane folds back on itself to produce two layers: visceral pleura and parietal pleura.
• The visceral pleura lines the outer surface of the lungs. Attached to our lungs.
• The parietal pleura (thoracic pleura) lines the inner surface of the chest wall. The inner thoracic wall, diaphragm, and lateral portion of the mediastinum are covered by the parietal pleura. Attached to our ribs.
• Importance of the pleural membrane:

  • It secretes pleural fluid, which allows your lungs to expand and recoil without collapsing.
  • Reduce the friction frequency or potential friction to its adjacent structures.
  • The pressure found in the pleural space provides the vacuum or the suction force so that the air can enter the lungs.
  • The pleural fluid ensures the close contact of the lungs and chest wall during respiration.
  • The pleural fluid provides lubrication and surface tension.
• The normal value of the pleural fluid inside the pleural membrane is approximately 10mL. If the pleural fluid exceeds the significant amount needed, it will compress the lungs and prevent it from expanding efficiently and the gas exchange will be inefficient so the patient will have a hard time breathing.