Final answer:
Pleural effusion is the correct term for the accumulation of fluids in the pleural space, which can lead to decreased lung volume and respiratory issues.
Step-by-step explanation:
The accumulation of fluids in the pleural space is known as pleural effusion. When fluid excessively builds in this area, it can restrict lung expansion, leading to difficulty in breathing and reduced lung volume. The pleural space is situated between the layers of tissue known as the visceral and parietal pleura that line the lungs and thorax respectively. In pleural effusion, the normally small amount of lubricating fluid within the intrapleural space increases, causing potential respiratory complications.