Pleurae and pleural cavities...
Each lung sits in a pleural cavity. Parietal pleura is the outer wall, visceral pleura is the inner wall, pleural cavity is the space between the two.
Both parietal and visceral walls are made of serous membrane composed of mesothelium and connective tissue.
The parietal pleurae are attached to the inside of the rib cage ( costal ) and superior surface of the diaphragm ( diaphragmatic ). It also borders on the mediastinum and cervical vertebrae ( it kind of pokes up through the thoracic inlet ).
The visceral pleurae are made of mesothelium and connective tissue and are in contact with the lungs.
In the pleural cavity is a watery fluid secreted by the pleurae that prefents friction during breathing.
- There are spaces in the pleurae not always filled with lung, they are called pleural recesses.
- Costodiaphragmatic recesses are in each pleurae and are filled by the most inferior part of the lungs on inhalation. On exhalation the lungs recede upward, leaving the costodiaphragmatic recesses empty.
Costomediastinal recess(es)(?) is/are where the mediastinal pleurae meets the costal pleura at the mediastinum.