Session 1.1i - TeachMeAnatomy - Thoracic Pleurae Flashcards
https://teachmeanatomy.info/thorax/organs/pleurae/
What do the pleurae refer to?
The SEROUS MEMBRANES that line the lungs and thoracic cavity.
What do the pleural line?
The lungs and thoracic cavity.
What is the function of the pleurae?
They permit efficient and effortless respiration.
How many pleurae do we have in the thoracic cage>?
There are two pleurae in the body - one covering each lung.
What is the structure of the pleurae?
They consist of a SEROUS MEMBRANE
What type of cells is the serous membrane?
A layer of simple squamous cells.
What is the structure of the serous membrane?
A layer of simple squamous cells, supported by connective tissue.
What is the simple squamous epithelial layer in the pleura known as?
The mesothelium
What is the mesothelium?
The simple squamous epithelial layer.
How can the pleura be divided?
Into two parts:
- VISCERAL PLEURA
- PARIETAL PLEURA
What does the visceral pleura cover?
The outer surface of the lungs
Which pleura covers the lungs?
The VISCERAL PLEURA
What is the parietal pleura?
It covers the internal surface of the thoracic cavity.
Which pleura covers the internal surface of the thoracic cavity?
PARIETAL PLEURA
Where are the two pleura continuous with each other?
At the HILUM of each lung.
What is between the visceral and parietal pleura?
A POTENTIAL SPACE, known as the pleural cavity.
Which pleura is thicker?
The parietal pleura is thicker than the visceral pleura
How can the parietal pleura be subdivided?
According to the part of the body that it is contact with:
- MEDIASTINAL PLEURA
- CERVICAL PLEURA
- COSTAL PLEURA
- DIAPHRAGMATIC PLEURA
What is the mediastinal pleura?
Covers the lateral aspect of the mediastinum (the central component of the thoracic cavity, containing a number of organ)
Which aspect of the mediastinum does the mediastinal pleura cover?
The lateral aspect
What is the mediastinum?
The central component of the thoracic cavity, containing a number of organ.
What is the cervical pleura?
Lines the extension of the pleural cavity into the neck.
What is the costal pleura?
Covers the inner aspect of the ribs, costal cartilages, and intercostal muscles.
What is the diaphragmatic pleura?
Covers the thoracic (superior) surface of the diaphragm.
What is the superior surface of the diaphragm known as?
The thoracic surface
Where does the visceral pleura extend into?
The interlobar fissures
Where do structures enter and leave the lung?
At the HILUM of each lung
What happens at the hilum of each lung?
This is where structures enter and leave the lung.
What does the pleural cavity contain?
A small volume of serous fluid
What is the function of the pleural cavity?
It contains a small volume of serous fluid, which as two major functions:
- lubrication
- surface tension
Describe the lubrication of the serous fluid.
The serous fluid in the pleural cavity lubricates the surfaces of the pleurae, allowing them to slide over each other.
Describe what happens to the surface tension produced by the serous fluid.
The serous fluid also produces a surface tension, pulling the parietal and visceral pleura together.
What is the function of the surface tension produced by the serous fluid?
This ensures that when the thorax expands, the lung also expands, filling with air.
What happens if air enters the pleural cavity?
The surface tension is lost (so the lung collapses?) This is known as a pneumothorax.
What is the pathophysiology behind a pneumothorax?
Pneumothorax = air in the pleural cavity.
This means the surface tension is lost.
The pleural cavity is not completely filled by the lungs, where?
Anteriorly and posteroinferiorly
Anteriorly and posteroinferiorly, what happens to the pleural cavity?
It is not completely filled by the lungs.
Anteriorly and posteroinferiorly, the pleural cavity is not completely filled by the lungs. What does this give rise to?
RECESSES
What are pleural recesses?
Where the opposing surfaces of the parietal pleura touch (and the visceral and parietal pleura are relatively distant)
What are the recesses present in the pleural cavity called?
There are two recesses present in each pleural cavity:
- COSTODIAPHRAGMATIC
- COSTOMEDIASTINAL
Where is the costodiaphragmatic recess?
Located between the costal pleurae and the diaphragmatic pleura
What is the space located between the costal pleurae and the diaphragmatic pleura called?
The COSTODIAPHRAGMATIC recess
Where is the costomediastinal recess?
Located between the costal pleurae and the mediastinal pleurae, behind the sternum.
What is the space located between the costal pleurae and the mediastinal pleurae called?
The COSTOMEDIASTINAL recess
Why is it important to know about pleural recesses?
These recesses [costodiaphragmatic and costomediastinal] are of clinical importance, as they provide a location where fluid can collect (such as in a pleural effusion).
In what condition can fluid collect?
Pleural effusion
What is pleural effusion?
Build-up of fluid in the pleura.
Is the neurovascular supply to each part of the pleura the same or different?
The two parts of the pleurae receive a different neurovascular supply:
What is the parietal pleura sensitive to?
Pressure, pain and temperature.
The parietal pleura is sensitive to pain, and therefore produces ___?
A well localised pain.
What is the parietal pleura innervated by?
The PHRENIC and INTERCOSTAL NERVES.
What is the blood supply to the parietal pleura?
It is derived from the INTERCOSTAL ARTERIES.
What is the visceral pleural not sensitive to?
The visceral pleura is not sensitive to pain, temperature or touch.
What does the visceral pleura detect?
Its sensory fibres only detect stretch.
What is the innervation to the visceral pleura?
Via the PULMONARY PLEXUS
The visceral pleural receives what innervation from the pulmonary plexus?
Autonomic
What is the pulmonary plexus?
A network of nerves derived from the sympathetic trunk and vagus nerve.
What is the arterial supply to the visceral pleura?
Arterial supply is via the BRONCHIAL ARTERIES
What are the bronchial arteries?
Branches of the descending aorta
As well as the visceral pleura, what do the bronchial arteries supply?
The parenchyma of the lungs.
(Clinical Relevance: Pneumothorax)
What is a pneumothorax commonly referred to as?
A collapsed lung
(Clinical Relevance: Pneumothorax)
What is ‘a collapsed lung’ more traditionally known as?
A PNEUMOTHORAX
(Clinical Relevance: Pneumothorax)
What is a pneumothorax?
A PNEUMOTHORAX occurs when air or gas is present within the pleural space.
(Clinical Relevance: Pneumothorax)
What happens when air or gas is present within the pleural space (pneumothorax)?
This removes the surface tension of the serous fluid present in the space, reducing lung extension.
(Clinical Relevance: Pneumothorax)
What are the clinical features of a pneumothorax?
- Chest pain
- Shortness of breath
- Asymmetrical chest expansion
(Clinical Relevance: Pneumothorax)
What might you find upon percussion of a patient with a pneumothorax?
The affected side may be HYPER-RESONANT
(Clinical Relevance: Pneumothorax)
Why might percussion change upon lung examination in a patient with a pneumothorax?
The affected side may be HYPER-RESONANT due to excess air within the chest.
(Clinical Relevance: Pneumothorax)
What are the classes of pneumothorax?
There are two main classes:
- SPONTANEOUS
- TRAUMATIC
(Clinical Relevance: Pneumothorax)
How does a spontaneous pneumothorax occur?
This occurs without a specific cause.
(Clinical Relevance: Pneumothorax)
How is a spontaneous pneumothorax sub-divided?
Into primary and secondary causes.
(Clinical Relevance: Pneumothorax)
What is a primary spontaneous pneumothorax?
A spontaneous pneumothorax with no underlying respiratory disease
(Clinical Relevance: Pneumothorax)
What is a secondary spontaneous pneumothorax?
A spontaneous pneumothorax with underlying respiratory disease present.
(Clinical Relevance: Pneumothorax)
What is a traumatic pneumothorax?
This occurs as a result of blunt or penetrating chest trauma
(Clinical Relevance: Pneumothorax)
What pathology can cause a traumatic pneumothorax?
A rib fracture
(Clinical Relevance: Pneumothorax)
How can a rib fracture occur to cause a traumatic pneumothorax?
Often seen in road traffic collisions.
(Clinical Relevance: Pneumothorax)
How do you treat a pneumothorax?
Treatment depends on identifying the underlying cause.
(Clinical Relevance: Pneumothorax)
How do you treat a primary pneumothorax?
These tend to be small and generally require minimal intervention.
(Clinical Relevance: Pneumothorax)
How do you treat a secondary pneumothorax?
This may require decompression to remove the extra air/gas in order for the lung to reinflate
(Clinical Relevance: Pneumothorax)
How do you treat a traumatic pneumothorax?
This may require decompression to remove the extra air/gas in order for the lung to reinflate
(Clinical Relevance: Pneumothorax)
What is the function of decompression in patients with a secondary/traumatic pneumothorax?
Removes extra air/gas in order for the lung to reinflate
(Clinical Relevance: Pneumothorax)
How is decompression achieved in secondary/traumatic pneumothorax?
This is achieved via the insertion of a CHEST DRAIN.
(Clinical Relevance: Pneumothorax)
What is a chest drain used for?
To remove extra air/gas in the lung, in order for it to reinflate.
Fig. 1
Label and caption the image
- Cervical
- Costal
- Mediastinal
- Diaphragmatic
The parts of the parietal pleurae.
Fig. 2
Label and caption the image
- Parietal pleural
- Visceral pleural
- Pleural cavity
- Lung hilum
The parietal and visceral pleura, and the pleural cavity. Note how the two layers of pleura are continuous at the hilum of the lung.
Fig. 3
Caption the image.
Radiographic appearance of a left pneumothorax
The pleural membranes are comprised of what type of epithelium?
A. Simple squamous
B. Pseudostratified columnar ciliated
C. Simple cuboidal
D. Transitional
A. Simple squamous
The pleura consist of a layer of simple squamous cells, supported by connective tissue. This simple squamous epithelial layer is also known as the mesothelium.
Air inside the pleura describes what condition?
A. Pleural effusion
B. Pneumothorax
C. Pneumonia
D. Ascites
B. Pneumothorax
Visceral pleura is sensitive to which of the following?
A. Pain
B. Temperature
C. Stretch
D. Touch
C. Stretch