pleural recess

The pleura are membranes that line the thoracic cavity (parietal pleura) and cover the lungs (visceral pleura). In a healthy state, these two layers are in contact, lubricated by a thin fluid that allows for smooth movement during breathing.12

Pleural recesses are spaces that form due to the shape of the pleural cavities and the lungs. These recesses act as reserve spaces, allowing the lungs to expand during inhalation. When the lungs expand, these recesses are partially opened, accommodating the increased lung volume.2

Disorders of the pleura can include inflammation (pleurisy), fluid accumulation (pleural effusion), or the presence of pus (empyema). If air enters the pleural cavity (pneumothorax), the lung can collapse.12