Final answer:
The lungs are separated by the mediastinum, and the pleura consists of two layers (visceral and parietal) that enclose the lungs. The space between these layers is called the pleural cavity.
Step-by-step explanation:
The 2 layers of the lungs are separated by the mediastinum, which is a space between the right and left pleurae. The pleurae, which are serous membranes, consist of two layers. The visceral pleura is the layer that covers the lungs, while the parietal pleura is the outer layer that connects to the thoracic wall, mediastinum, and diaphragm. These two layers create the pleural cavity, which is the space between them.