Final answer:
The intrapleural space is the area with negative pressure between the chest wall and lung, containing pleural fluid to reduce friction during breathing and maintained at -4 to -8 mm Hg.
Step-by-step explanation:
The fluid-filled region that has a negative pressure and lies between the interior surface of the chest wall and the exterior surface of the lung is the intrapleural space. This space contains a small amount of pleural fluid which acts as a lubricant during the movement of breathing, allowing the lung and the chest wall to move with reduced friction.
Competing forces within the thorax, such as the elasticity of the lungs and the surface tension of alveolar fluid, contribute to the negative pressure in this space, ranging from -4 to -8 mm Hg during the breathing cycle. Too much or too little pleural fluid can affect this delicate balance, hence, the level is tightly regulated by the mesothelial cells and drained by the lymphatic system to maintain the necessary negative pressure.