Pleurae Flashcards
What is each lung enclosed by?
A serous pleural sac consisting of two membranes, the pleurae.
What does the visceral pleura do?
It covers the lungs and is adherent to all its surfaces, including the horizontal and oblique fissures, it cannot be separated from the lungs.
What does the parietal pleura do?
It lines the pulmonary cavities, it is adherent to the thoracic wall, the mediastinum and the diaphragm.
Are the two pleura continuous?
Yes, the visceral pleura reflects off the root of the lungs to become the parietal pleura and vice versa.
What 4 parts is the parietal pleura subdivided into?
Costal pleura- covers the internal surfaces of the thoracic wall.
Mediastinal pleura- covers the lateral aspects of the mediastinum.
Diaphragmatic pleura- covers the superior aspect of the diaphragm on each side of the mediastinum.
Cervical pleura- extends through the superior thoracic aperture forming formed pleura over the apex of the lung.
What is the pleural cavity?
The potential space between the layers of pleura.
What is the pleural cavity filled with?
Serous pleural fluid which lubricates the pleural surface and allows the layers of the pleura to slide smoothly over each other during respiration.
What else does the fluid in the pleural cavity do?
It provides the surface tension that keeps the surface of the lung in contact with the thoracic wall; consequently the lung expands and fills with air when the chest expands and the diaphragm flattens.
How does a lung collapse?
If a significant amount of air or fluid enters the pleural cavity, the surface tension adhering the visceral and parietal pleura is broken and the pleural cavity becomes a real space. As a result the lung collapses.
What is the name of air rushing into the pleural cavity?
Pneumothorax.
What is the name of fluid accumulating in the pleural cavity?
Hydrothorax.
What is it called if blood rushes into the pleural cavity?
Haemothorax.
