pleuraholten

Pleuraholten, or pleural cavities, are paired, fluid-filled potential spaces between the parietal and visceral layers of the pleura that surround the lungs. Each cavity is enclosed by a continuous serous membrane: the parietal pleura lines the chest wall, the mediastinum, and the superior aspect of the diaphragm; the visceral pleura covers the outer surface of the lungs. Normally the two layers are opposed and contain a small amount of pleural fluid, which provides lubrication to reduce friction during respiration.

Anatomical features include extensions from the chest wall to the diaphragmatic and mediastinal surfaces, with the cavities extending from the cervical pleura (cupula) above the first rib to the inferior costodiaphragmatic recesses at the base. The recesses expand during inspiration and are common sites where fluid can accumulate. The mediastinum separates the two pleural cavities.

Vascular and nerve supply differ between layers. The parietal pleura receives sensory innervation from intercostal nerves and, for the central part, the phrenic nerve, making it sensitive to pain; the visceral pleura is innervated by autonomic fibers and is less sensitive to painful stimuli. Blood supply follows the pleural layers: the parietal pleura receives branches from intercostal and internal thoracic arteries, while the visceral pleura is supplied primarily by bronchial arteries and the pulmonary circulation.

Function and clinical relevance: The pleural cavities permit smooth lung expansion by maintaining a negative intrapleural pressure and by providing low-friction surfaces. Breach of the pleural space can lead to pneumothorax (air), pleural effusion (fluid), hemothorax (blood), or empyema (pus). Pleuritis and pleural thickening can restrict movement. Diagnostic imaging, including chest radiographs, ultrasound, and CT, helps evaluate pleuraholten and related pathology.

Etymology and usage: pleuraholten is the Dutch term for the pleural cavity; in English, the terms pleural cavity or pleural spaces are used.