Lungs and Ventilation Pathway - LO 1
1. Describe the pleura, including the recesses/potential spaces created by the pleural sacs. Understand how this anatomy relates to conditions/disorders or clinical procedures.
The pulmonary cavities contain the pleurae. The outer margins of the pulmonary cavities are lined with parietal pleurae, whereas visceral pleurae adhere to all surfaces of the lungs.
The parietal pleurae each have three parts:
costal,
diaphragmatic, and
mediastinal.
Cervical pleurae (extensions of the mediastinal and costal parts) form domes over the apices of each lung.
The spaces between parietal and visceral pleurae are the pleural cavities.
There are two important recesses associated with the pleural cavities. Both are potential spaces between reflections of different parts of parietal pleurae.
Costodiaphragmatic recesses: potential spaces between the diaphragmatic and costal parietal pleurae. The lungs (covered by visceral pleura) sit above these recesses, and may enter into them during inspiration.
The margins of this recess vary based on anatomical line:
Between 6th - 8th ribs at the midclavicular line
Between 8th - 10th ribs at the midaxillary line
Between 10th - 12th ribs at the paravertebral line
Costomediastinal recesses: potential spaces between the costal and mediastinal parietal pleurae
The left costomediastinal recess is larger because of the location of the heart and the cardiac notch of the left lung.
