The Thoracic Cavity

Divided into three major divisions:

A. The right pleural cavity

B.The mediastinum

C. The left pleural cavity

The pleura and pleural cavities

This is a thin membrane that lines the lungs and the chest wall. It consists of two layers:

• Parietal pleura: Lines thoracic cage, mediastinum and superior surface of the thoracic diaphragm.
  Also projects above the 1 st rib and the clavicle into the neck.
  
  
• Visceral pleura : Lines the lungs
  

Parts of parietal pleura

Named according to the structures they cover:

1. Costal pleura:
2. The mediastinal pleura
3. The diaphragmatic pleura:
4. The pleural cupola: or cervical pleura.

Lines of pleural reflection

• The sternal pleural reflection

• The costal pleural reflection:

• Vertebral pleural reflection:

• Mediastinodiaphragmatic pleural reflection