To understand the relationship of pleura and lungs, imagine yourself pushing your fist into a partially inflated balloon. The part of the balloon wall adjacent to the skin of your fist is comparable to visceral pleura, the remainder of the balloon is comparable to parietal pleura. The air filled cavity between the two layers of balloon is analogous to the pleural cavity.
To view the the animation, press the begin button below, then press the next button (triangular button). To see the animation again, press the replay button (between the two triangular buttons).