Pleura

Pleural cavities

The pleural cavities are closed sacs enveloping each lung. Each cavity comprises a visceral layer (green) and a parietal layer (blue). The visceral layer is closely apposed to the lungs and cannot be dissected from the surface. The parietal layer is thicker and is attached to the walls of the thorax (e.g., diaphragm, ribs, etc). The layers are continuous at the hilum of the lung.

It is important to understand the reflections of the parietal and visceral pleura on the thoracic wall as seen from anterior, lateral, and side. Generally, the visceral pleura (lungs) are 2 ribs more superior than the parietal pleura at mid inspiration.

Anteriorly (1) the pleura reach the midline at rib 2 (2) the pleura deviate to the left at rib 4 (cardiac notch) (3) the pleura deviate to the right at rib 6 (4) the visceral pleura reaches rib 6 at the mid-clavicular line (vertical bar) (4) the parietal pleura reaches rib 8 at the mid-clavicular line (arrow)	Laterally the visceral pleura reaches rib 8 at the mid-axillary line (vertical bar) the parietal pleura reaches rib 10 at the mid-axillaryr line	Posteriorly the visceral pleura reaches rib 10 the parietal pleura reaches rib 12

John A. McNulty

Last Updated: March 28, 1996
Created: 1 March 1996

It is important to understand the reflections of the parietal and visceral pleura on the thoracic wall as seen from anterior, lateral, and side. Generally, the visceral pleura (lungs) are 2 ribs more superior than the parietal pleura at mid inspiration.

Anteriorly

Laterally

Posteriorly