Pleurae, Pleural Cavities, and Mediastinum Flashcards
What are the three subdivisions of the thoracic cavity?
2 pleural cavities and 1 mediastinum
What does the mediastinum contain?
Heart, great vessels, trachea, esophagus, etc.
What is a pleura?
Thin membrane which lines the inner surface of the thoracic cavity and covers the surface of the lung
What is the parietal pleura?
Lining of the inner surface of the thorax
What does the visceral pleura encompass?
Intimately invests the lung
What is the pleural cavity?
Potential space between the parietal and visceral pleurae
What is the function of the pleural fluid and where is it located?
Lubricates the pleurae to minimize the friction between the parietal and visceral layers, facilitating movement of the lungs (located in the pleural cavity)
What is the ONLY thing that should be in the pleural cavity?
Pleural fluid
What are the 4 parts of the parietal pleura?
Costal, mediastinal, diaphragmatic, and cervical pleurae
Cervical pleura covers what?
Apex of the lung
What are pleural recesses and their function?
Spaces found between two folds of parietal pleura that allow expansion of the lung during inspiration
What is the costodiaphragmatic recess and where is it located?
Space formed where the costal and diaphragmatic pleurae meet, midaxillary line
What is the costomediastinal recess?
Space formed where the costal and mediastinal pleurae meet
Which pleural recess is rarely used for thoracentesis due to its proximity to the heart?
Costomedistinal recess
In which pleural recess does fluid tend to accumulate and therefore thoracentesis is performed?
Costodiaphragmatic recess
At which intercostal space is thoracentesis performed and during which act of respiration?
Intercostal space 9, expiration
Why is thoracentesis performed above the rib?
To avoid the vessels and nerve near the costal groove
What is the blood supply for the parietal pleura?
Intercostal arteries, internal thoracic artery, and superior phrenic artery
What is the blood supply for the visceral pleura?
Bronchial artery
What is the innervation of the parietal pleura?
Intercostal nerves, subcostal nerve, phrenic nerve
What is the innervation of the visceral pleura?
JK, there is no sensory innervation (insensitive to pain)
Which pleura is highly sensitive to pain and dermatome-based?
Parietal
What is pneumothorax?
When the pleural cavity fills with air
How does pneumothorax appear on an x-ray?
Dark
What are the three causes of pneumothorax?
Trauma, disease, or a congenital weak spot
Congenital weak spots leading to pneumothorax are common among what type of individuals?
Tall people
What is tension pneumothorax?
Where a flap is present on the visceral pleura instead of a hole allow air to enter during inspiration but not leave during expiration
What is a big complication of tension pneumothorax?
Cavity inflates pushing mediastinum to opposite side compressing the other lung (therefore, fatal)
Is regular pneumothorax fatal?
No
What is hemothorax?
When the pleural cavity fills with blood
What is hemopneurothorax?
When the pleural cavity is filled with both blood and air
During lung collapse (atelectasis), what conditions involving the thoracic cavity are present?
Hemothorax and pneumothorax
What is pleuritis?
Inflammation of the pleurae which leads to adhesions between the parietal and visceral pleura
Why is pleuritis especially painful?
Its super sensitivity to pain
How can pain be referred to the shoulder in pleuritis?
Via the phrenic nerve (C3, C4, and C5)
What is the sound called during pleuritis that can be heard via auscultation?
Pleural friction rub
What is the mediastinum?
Space between the pleural cavities
What does the mediastinum contain (general)?
Everything except the lungs and pleurae
At what vertebral level is the imaginary line dividing the mediastinum into its superior and inferior parts?
T4 and T5
The sternal angle is important because it indicates what five things?
Boundary between the superior and inferior mediastinum, articulation of the second rib with the sternum, aortic arch, bifurcation of the trachea into the left and right main bronchi, and upper border of the pulmonary trunk
What are the ten things found in the superior mediastinum?
Superior vena cava, brachiocephalic veins, arch of the aorta & branches, thoracic duct, trachea, esophagus, thymus, vagus nerve, left recurrent laryngeal nerve, phrenic nerve
What are the three subdivisions of the inferior mediastinum?
Anterior, middle, and posterior mediastinum
What is the location of the anterior mediastinum?
Anterior to pericardial sac and posterior to the sternum
What are the contents of the anterior mediastinum?
Thymus, lymph nodes, and sternopericardial ligaments
What is the location of the middle mediastinum?
Bounded by the pericardial sac
What are the contents of the middle mediastinum?
Heart, pericardium, roots of the great vessels, main bronchi, and phrenic nerve
What is the location of the posterior mediastinum?
Posterior to the pericardial sac and anterior to T5-T12
What are the contents of the posterior mediastinum?
Esphagus, thoracic aorta, azygos vein, hemiazygos vein, thoracic duct, vagus nerve, splanchnic nerves
