The space between the membranes (called the pleural cavity or intrapleural space) is filled with a thin, lubricating pleural fluid. The pleura is comprised of two layers: The visceral and parietal ...

In dogs, the pleural cavity exists as a potential space, with the visceral and parietal pleurae separated only by a thin layer of pleural fluid. Dogs have 13 paired ribs, numbered 1–13 ...