Pleura

Question 1

Describe the 2 layers of pleura and the cavity formed by them?

Answer 1

The pleura covers the lungs. There are 2 type of pleural layers:

• Parietal pleura-on the outside
• Visceral pleura-on the inside, adheres to the lung parenchyma

These layers form a pleural cavity, which is lined with mesothelium cells (simple squamous epithelium). Pleural cavity contains lubricating serous fluid that reduces friction and allows for lung movement.

Question 2

Describe the parts of the parietal pleura?

Answer 2

• Costal pleura-associated with the ribs and intercostal spaces
• Diaphragmatic pleura-associated with the diaphragm
• Mediastinal pleura-associated with the mediastinum
• Cervical pleura-covers the cervical extension of parietal pleura, near the apex

Supporting the parietal pleura from the neck, there is a connective tissue called the..

• Suprapleural membrane- (supra~above) between the transverse process of C7 and medial margin of rib I

The mediastinal pleura reflects to form a sleeve-like covering (think of T-shirt hole) where the NVS structures pass through, called the root of the lung. The root of the lung joins the medial surface of the lung called the hilum of the lung.

Question 3

What are the 2 recesses of the pleura and what are their function?

Answer 3

Pleural recesses, as the name suggests are spaces of the pleural cavity which is not filled by the lung. These recesses allow..

• Lungs to further expand during forced inspiration
• Fluid from infection etc to collect (for example during a pleural effusion).

There are 2 pleural recesses..

• Costomediastinal recess-between the costal pleura and mediastinal pleura. Largest on the left side overlying the heart
• Costodiaphragmatic recess-between the costal pleura and diaphragmatic pleura.