Synonym
pleura, costal pleura (anatomically not quite correct)
Definition
The pleura lines the chest cavity from the inside. It serves as a shifting layer between the lung and the wall of the thoracic cavity and ensures that the lung is adequately unfolded.
Structure
The pleura consists of two leaves. In this respect, the name of the pleura as “pleura” in the vernacular is not quite correct, since the pleura means only one of the two pleural leaves. The narrow space between the two pleural leaves is called the pleural gap.
In this gap there is a 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 ensures that the pleural leaves glide smoothly against each other.
- A visceral (viscera – intestines) that lies adjacent to the lungs (visceral pleura or lung fur) and
- A parietal (paries – wall), which lies against the chest wall (pleura parietalis or pleura of the chest or ribcage).
Sections
The pleura is divided into four sections according to its location. At the points where the different sections merge into each other, the pleura forms recesses, so-called recessesus, which are impressive as pocket-shaped bulges. They serve as reserve spaces into which the lung can unfold during exhalation.
The largest of these folds is the recessus costodiaphragmaticus, which lies between the pars diaphragmatica and the pars costalis. A further three recesses are distinguished, the There are two small pleura-free triangles in the area of the sternum. The thymus triangle and the heart triangle.
These pleura-free areas are important, for example, when a pericardiocentesis has to be performed as an emergency procedure, for example when fluid has accumulated in the pericardium (pericardial tamponade). If the heart is not punctured in a pleura-free triangle, a pneumothorax is provoked, as the pleura is injured, causing air to enter the chest cavity from the outside.
- The pars costalis lies against the ribs,
- The pars diaphragmatica of the diaphragm,
- The pars mediastinalis lines the center of the thorax, while
- The pleura cervicalis with the cupula pleurae (pleural dome) forms the upper section.
- Recessus costomediastinalis, the
- Recessus vertebromediastinalis and the
- Recessus phrenicomediastinalis.