1. Methods The morphosis of the mesothelium of the parietal pleura in rat were investigated by intrapleura injection with tracers and observed by scanning electron microscope.

2. The parietal pleura lines the inside of the chest and covers the ribs and the pericardium.

3. Objective To observe the permeability of parietal pleura and discuss the absorptive pathway of the particulates in pleural cavity.

4. The parietal pleura lines the inner chest wall and the visceral pleura encases the lungs.

5. Chest CT scan showed diffuse masses on the visceral and parietal pleura.

6. At a single millimeter in thickness, the visceral pleura is barely half the width of the parietal pleura.

7. The ease of which it can be removed is dependant on which of the pleural surfaces becomes malignant: the parietal pleura or the visceral pleura.