The Pleural Cavities and Lungs
T/F: The lungs completely fill both the anterior and posterior-inferior regions of the pleural cavities.
False. The lungs *do not* completely fill the anterior or posterior-inferior regions of the pleural cavities.
What are the borders of the pleural cavities?
Superiorly - The pleural cavities extend above the 1st rib, into the neck Inferiorly - They extend to just above the level of the costal margin Medially - The wall of each pleural cavity is the mediastinum
Reading
*Read Pages 200-208 in the 1st Ed. of Grays or Pages 224-232 in the 2nd Ed. of Grays Anatomy for Students for important descriptions of how bony landmarks of the thoracic skeleton relate to underlying heart and lung tissue. Knowledge of these relationships is key when trying to listen to heart and lung sounds.
How far superior do the pleural cavities and lungs extend?
Above the first costal cartilage and thus into the neck.
How is it physically found?
Begin at the hilum and follow the branching of either the bronchi or the pulmonary arteries. Lung tissue will be dissected away in the process
Which lung approaches closest to the midline, and in what part of the thorax?
Both lungs and pleural cavities approach midline in the region of the upper sternum, but neither the left lung or pleural cavity come as close to midline as the right int the region of the lower sternum. This is due to displacement by the heart.
What nerve innervates the visceral pleura and other structures of the lung?
GVA and GVE fibers distributed through the pulmonary plexus. These fibers come from the vagus nerve and the sympathetic chain
What are the bronchopulmonary segments?
It is an area of lung supplied by a segmental (tertiary) bronchus and its accompnaying pulmonary artery branch.
What/where is the cervical (cupola) pleura?
It is the dome of pleura lining the cervical extension of the pleural cavity
What is the name of the region of the lung that the root joins at the medial surface of the lung?
It is the hilum.
What is the first pleural layer encountered when you remove the anteior chest wall?
It is the parietal pleura.
What/where is the mediastinal pleura?
It is the pleura covering the mediastinum
What/where is the costal pleura?
It is the pleura related to the intercostal spaces and ribs
Where/what is the diaphragmatic pleura?
It is the pleural covering the diaphragm.
What is a pleural cavity? What is the normal state of the pleural cavity?
It is the potential space between the parietal and visceral pleura. Normally each space contains only a small amount of serous fluid, allowing the lung, which is covered by visceral pleura, to slide freely over the parietal pleura
What is the relevance of the bronchopulmonary segment?
It is the smallest, functionally independent region of a lung that can be isolated and removed without affecting adjacent segments.
What is the root of the lung?
It refers to the tubular sleeve of mediastinal pleura that surrounds structures passing between the lungs and the mediastinum.
Bronchopulmonary segments of the left lung
Lateral View
The bronchopulmonary segments of the right lung
Lateral View
Both lungs bronchopulmonary segments
Lateral view
Bronchopulmonary segments
Medial View
When do the lungs expand into the unfilled regions of the pleural cavities (anterior and posterior-inferior)?
Only during forced inspiration.
What are the two types of pleura?
Parietal - Associated with the walls of the pleural cavity Visceral - The layer adherent to the surface of the lung
What lymph structures drain the lung?
The Tracheobronchial lymph nodes
What lymph structure does the left lung drain into? What is the exception?
The left bronchomediastinal nodes and trunk. The exception is that the lower portion of the left lung drains into right bronchomediastinal nodes and trunk.
Where do the phrenic nerves pass?
The phrenic nerves are adherent to the pericardium (sac of the heart). These nerves pass just anterior to the root of the lung on their course to innervate the diaphragm.
What lymph structure does the right lung drain into?
The right bronchomediastinal nodes and trunk
Which bronchus is wider and straighter than the other? What is the clinical consequence?
The right main bronchus is wider and straighter than the left and is therefore a more likely site for aspirated material.
How many bronchopulmonary segments exist?
There are 10 in the right lung and 8 in the left. The text lists each side of the lung as having 10 bronchopulmonary segments, but some of them fuse in the left lung so there are only 8.
What are the two pleural cavities?
There are two pleural cavities, on either side of the mediastinum. They surround the lungs.
Where do the bronchial arteries come from?
These vessels typically arise from the thoracic aorta or one of its branches.
What are the costomediastinal and costodiaphragmatic recesses?
They are recesses that are potential spaces in which fluid may accumulate.
What do the bronchial arteries do?
They supply the nutritive support to the pulmonary tissues.
Where do the tributaries of the pulmonary veins pass?
They tend to pass between bronchopulmonary segments.
T/F: The parietal and visceral pleura are continuous at the hilum
True
Do the left or right lungs entirely fill their respective pleural cavities?
While the pleura reflects onto the diaphragm, neither the right nor the left lung fill their respective pleural cavities. This can be seen easily anteriorly, especially inferiorly.