Anatomy: Pleura and Lung Flashcards
What is the pleura lined by?
The pleura isa fibrous tissue lined by a single layer of squamous cells (mesothelium)
Explain the two layers of the pleura
Parietal pleura - layer lining thoracic wall (rib cage, vertebrae, and diaphragm)
Visceral pleura - also known as the pulmonary pleura / layer completely covering the lung. At the root of the lung it is continuous with mediastinal parietal pleura.
What is the pleural cavity?
The pleural cavity is a space between the visceral pleura and the parietal pleura.
Under what conditions can a potential pleuritic space become a real space?
NB: In the living body potential space and visceral pleura touches the parietal pleura. This no longer becomes potential (virtual) under pathological conditions
Pathological conditions such as:
Pneumothorax = air present in the pleural cavity
Excess fluid present in the pleural cavity resulting in compression of lungs and hence breathing difficulties, includes the following:
Pleural effusion = fluid can be serous
Haemothorax = blood in the pleural cavity resulting from trauma
What are the subdivisions of parietal pleura?
- Costal pleura
- Mediastinal pleura
- Diaphragmatic pleura
- Cervical pleura
Description.
- Costal pleura lines the inner surface of the thoracic wall
- Mediastinal pleura lines the mediastinum
- Diaphragmatic pleura lines the superior surface of the diaphragm
- Cervical pleura (cupula) extends superior to the first rib
Which type of parietal pleura is continuous with all layers?
Mediastinal pleura
How far does the cervical pleura extend into the root of the neck?
3-4cm above the level of the first costal cartilage.
Summit: 2-3cm above the medial third of the clavicle
Which tissue connects the diaphragm to the diaphragmatic pleura?
The phrenicopleural fascia
What is a pleural recess?
These are areas where parietal pleura contacts (meets) parietal pleura
What are the types of pleural recesses?
- Costomediastinal recess
2. Costodiaphragmatic recess
What is the costomediastinal recess?
There are 2 costomediastinal recesses (Left and right)
The costomediastinal recess occurs posterior to the sternum where the costal pleura meets the mediastinal pleura
It is the potential space behind the sternum and costal cartilages, where the anterior margin of the lung fails to reach the anterior margin of pleura.
What is the costodiaphragmatic recess?
There are two also (left and right) located in the most inferior limits of the parietal pleura where costal pleura meets the diaphragmatic pleura.
What is the purpose of the costomediatinal recess?
Purpose of the potential space is to assist the lung expansion during deep inspiration.
- costodiaphragmatic recess is more significant.
What are parietal folds?
These are lines of pleural reflection which can occur where COSTAL PLEURA meets DIAPHRAGMATIC PLEURA or MEDIASTINAL PLEURA
What is the extent of the costodiaphragmatic recess?
Extends from the 8th to the 10th rib along the mid-axillary line.
What is the relation the the diaphragmatic pleura and the lung?
The lower limit of the lung is about 5cm above the lower limit of the pleura
What is the endotharacic fascia?
Connective tissure between the thoracic walla and costal parietal pleura
What is the purpose of the endothoracic fascia?
Provides cleavage plane for surgical separation of pleura from thoracic wall
What is the pulmonary ligament?
It is a double layered parietal fold which extends beyound the root of the lung and hence is inferior to the root and anterior to the esophagus.
What is the arterial supply of the parietal pleura?
Supplied by the intercostal, internal thoracic and musculophrenic arteries.
Memba: Parietal pleura is near to the vertebrae and intercostal muscles so it makes sense.
What is the venous drainge of the parietal pleura?
Drains into the azygous system of veins.