The parietal layer of the pleura secretes pleural fluid. This fluid is essential for lubricating the surfaces of the pleura, the thin tissue lining the chest cavity and lungs, allowing them to move smoothly during respiration.
Understanding Pleural Fluid Secretion and Reabsorption
- Secretion: Pleural fluid is primarily secreted by the parietal pleura, specifically in the less dependent areas of the pleural cavity. This secretion occurs via a process called bulk flow. [Source: Physiology and pathophysiology of pleural fluid turnover, https://pubmed.ncbi.nlm.nih.gov/9032518/]
- Reabsorption: The lymphatic system, primarily in the diaphragmatic and mediastinal regions of the parietal pleura, is responsible for reabsorbing the pleural fluid. [Source: Pleural fluid is secreted by the parietal layer of the pleura by way of bulk flow and reabsorbed by the lymphatics in the most dependent parts of the parietal pleura, primarily the diaphragmatic and mediastinal regions.]
- Normal Fluid Volume: The pleural space normally contains only a small amount of fluid (approximately 5-10 mL). [Source: The pleural space is normally filled with ~5 to 10 mL of serous fluid, which is secreted mainly from the parietal pleura at a rate of 0.01 mL/kg/h and ...] An excess accumulation leads to a condition called pleural effusion. [Source: A pleural effusion is accumulation of excessive fluid in the pleural space, the potential space that surrounds each lung. Under normal conditions, pleural ...]
Clinical Significance
Understanding pleural fluid production and reabsorption is crucial in diagnosing and managing various conditions, including pleural effusions. These effusions can arise from various causes, including infections, cancer, and heart failure, and may necessitate medical intervention. [Source: Malignant pleural effusion (MPE) is a common, devastating complication of a wide array of malignancies, and it is associated with impaired ...]
