Parietal pleura

Parietal pleura is the outer layer of the pleura, the serous membrane which envelopes the lungs and lines the walls of the thoracic cavity. The parietal pleura is attached to the chest wall, while the inner layer, the visceral pleura, is attached to the lungs. The space between these two layers is known as the pleural cavity, which contains a small amount of pleural fluid that lubricates and allows the two layers to slide over each other during respiration.

Structure

The parietal pleura is divided into four parts: the cervical, costal, diaphragmatic, and mediastinal pleurae. The cervical pleura (pleura of neck) extends into the neck over the apex of the lung. The costal pleura lines the inner surface of the rib cage. The diaphragmatic pleura lines the top of the diaphragm, and the mediastinal pleura attaches to the other organs in the mediastinum, the space between the lungs.

Function

The main function of the parietal pleura is to produce pleural fluid that fills the pleural cavity. This fluid serves two main purposes: it acts as a lubricant, allowing the lungs to expand and contract without friction, and it creates a pressure gradient which helps keep the lungs inflated.

Clinical significance

Damage or disease of the parietal pleura can lead to a number of medical conditions. Pleurisy is an inflammation of the pleura that can cause sharp chest pain. Pneumothorax is a condition where air enters the pleural cavity, causing the lung to collapse. Pleural effusion is a buildup of fluid in the pleural cavity, which can put pressure on the lung. These conditions can be diagnosed using a chest X-ray or CT scan, and may be treated with medication or surgery.

See also

• Pleura
• Visceral pleura
• Pleural cavity
• Pleural fluid
• Respiration (physiology)