Pleura

synonym

Pleura, pleura (anatomically not entirely correct)

definition

The pleura lines the inside of the chest cavity. It serves as a shifting layer between the lungs and the wall of the chest cavity and ensures adequate development of the lungs.

construction

The Pleura consists of two leaves.

• One visceral (viscera - Guts), that the lung (pleura visceralis or lung pleura) and
• one parietal (paries - wall) that the Chest wall (pleura parietalis or pleura or pleura).

In this respect, the designation of the pleura as "Pleura“Not quite right in the vernacular, since the pleura only means one of the two pleural leaves. The narrow space between the two pleural leaves is called the Pleural space designated. There is one in this gap negative pressure, which plays an important role in the full development of the lungs.
The cells of the superficial layer of the pleural leaves, the Mesothelium, secrete a fluid that allows the pleural leaves to slide smoothly together.

Sections

The pleura is divided into four sections according to its location.

• The Pars costalis lies the Ribs on,
• the Pars diaphragmatica the diaphragm,
• the Pars mediastinalis dresses the center of the Rib cage off while
• the Cervical pleura with the cupula pleurae (Pleural dome) forms the upper section.

At the points where the various sections merge, the pleura forms enveloping traps, so-called recesses, which appear as pocket-shaped bulges. They serve as reserve spaces into which the lungs can expand during exhalation.

The largest of these envelope folds is that Costodiaphragmatic recess, it lies between the pars diaphragmatic and the pars costalis. There are three further recesses, den

• Costomediastinal recess, the
• Vertebromediastinal recess and the
• Phrenicomediastinal recess.

There are two small pleural-free triangles in the area of ​​the Sternum (sternum). The Thymus triangle and the Heart triangle. These pleural-free areas are important, for example, when a pericardial puncture has to be performed as an emergency procedure, for example when there is fluid in the Pericardium has accumulated (Pericardial tamponade). If you don't puncture the heart in a pleura-free triangle, you provoke one Pneumothoraxbecause you injure the pleura and thus trigger an entry of air from the outside into the chest cavity.

function

The lungs undergo large changes in volume during a breathing cycle. It expands on inspiration (inhalation), while it becomes smaller on expiration (exhalation).

The pleura, thanks to its smooth surface and secretion of fluid, enables the lungs to slide smoothly during their volume changes. Various diseases can lead to roughening of the pleura or sticking of the pleural leaves, which can manifest itself in breathing difficulties.

The negative pressure that prevails in the pleural space, the space between the two pleural leaves, is also essential for adequate development of the lungs. When you inhale, the chest expands and the diaphragm sinks down. Due to the negative pressure in the pleural space, the lungs follow this expansion of the thorax and can thus be filled with air. With a pneumothorax, which is associated with an injury to the pleura, this negative pressure is lost and the lungs shrink. Depending on the size of the defect, significant breathing difficulties result.
In the worst case, a tension pneumothorax develops. This means that the leak in the pleura allows air to enter the chest cavity from the outside, but no air can escape, so there is a kind of valve mechanism and the chest continues to "pump" itself up with air, which causes rapid compression of the lungs with massive breathing difficulties. A tension pneumothorax is a clinical emergency.

Other clinical aspects

At a Pleural effusion collects in Pleural space Liquid. It is mostly found in the Costodiaphragmatic recess and can there by means of a X-ray image be diagnosed. A pleural effusion can, depending on its extent, significantly impair the breathing and it is often an indication of another disease such as a

• inflammation or one
• tumor.

Such an effusion is usually punctured, with a cannula inserted on the side of the patient's back and the liquid punctured. A puncture is important here above of Rib margin, since the nerves and vessels run along the lower edge of the ribs.