Visceral Pleura (Left Lung)

Structure

The pleura consists of two layers, an inner visceral and an outer parietal layer. The inner visceral pleura closely invests the surface of the lungs and sits within the fissures of the lung. In cadaveric dissection, it is not possible to separate the visceral pleura from the lung tissue. The visceral and parietal pleura are continuous at the hilum where they form the pulmonary ligament.

Anatomical Relations

Since the visceral and parietal pleurae are continuous at the hilum, they form a closed sac called the pleural cavity, which contains serous fluid. Due to the position of the heart, the left pleural cavity is smaller than the right.

Function

Within the pleural cavity, a thin layer of fluid is produced by the serous epithelial membrane lining the visceral and parietal pleurae. In addition, the visceral pleura invests all surfaces of the lung and gives the lung a shiny appearance. This smooth surface and fluid layer allow friction-free movement during respiration.

Arterial Supply

The visceral pleura is supplied, along with the lungs, via the bronchial arteries. At the hilum of each lung, the bronchial arteries branch around the primary bronchus and pleural branches arise from here. They supply the mediastinal visceral pleura, the interlobar surfaces, the apex, and a portion of the diaphragmatic visceral pleura.

Venous Drainage

The visceral pleura receives afferents from the pulmonary plexus that course with the bronchial vessels (Standring, 2016).

Innervation

The visceral pleural afferents from the pulmonary plexus course with the bronchial vessels (Standring, 2016).

Lymphatic Drainage

Lymph from visceral pleura is drained via the superficial pulmonary lymphatic plexus.

List of Clinical Correlates

- Pneumothorax

- Hydrothorax

- Hemothorax

- Chylothorax

- Pleurectomy

- Pleurisy

References

Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41 edn.: Elsevier Limited.