Pleura and Lungs Flashcards
What are the pleurae? (2)
o Each lung is invested by and enclosed in a serous pleural sac of 2 continuous membranes
o Pleural cavity- potential space between the layers of pleura containing serous pleural fluid
What is the visceral pleura? (3)
- Closely covers the lungs and adheres to all its surfaces, including surfaces within fissures
- Provides lung with smooth and slippery surface, allowing it to move freely on parietal pleura
- Continuous with the parietal pleura at the hilum of the lung
What is the parietal pleura? (3)
- Lines pulmonary cavities
- Adheres to the thoracic wall, mediastinum and diaphragm
- Thicker than visceral pleura
What are 3 parts of the parietal pleura? (3)
- Costal part: covers the internal surfaces of the thoracic wall and is separated from that surface by endothoracic fascia
- Mediastinal part: covers lateral aspects of the mediastinum and reflects laterally onto the root of the lung to become continuous with the visceral pleura
- Diaphragmatic part: covers superior surface of diaphragm on each side of the mediastinum. Phrenicopleural fascia connects diaphragmatic pleura to diaphragm
What is the cervical pleura?
Cervical pleura: covers the apex of the lung and projects above the 1st rib and clavicle
What are the lines of pleural reflection?
Lines along which the parietal pleura changes direction as it passes from one wall of the pleural cavity to another.
3 lines of pleural reflection on each side:
- Left and right sternal lines
- Costal lines
- Vertebral lines
What are the characteristics of the Left and right sternal lines? (6)
- Occur where costal pleura is continuous with mediastinal pleura
- Run inferomedially passing posterior to sternoclavicular joints
- Left and right lines meet at the anterior median line (midsternal line) at level of the sternal angle.
- Right line- continues down anterior median line until xiphoid process where it turns laterally
- Left line- continues down anterior median line until 4th costal cartilage where it turns laterally to form the cardiac notch
What are the characteristics of the Costal lines? (5)
- Occurs where costal pleura becomes continuous with diaphragmatic pleura inferiorly
- Right line- proceeds laterally from the anterior median line
- Left line- begins at the midclavicular line due to bare area of pericardium on left side
- Continue symmetrically when they proceed laterally, posteriorly and then medially, passing obliquely across the 8th rib in the midclavicular line and the 10th rib in the midaxillary line
- Becomes continuous posteriorly with the vertebral lines at the necks of the 12th
ribs inferior to them
What are the vertebral lines? (4)
- Rounder, gradual reflection
- Occurs when costal pleura becomes continuous with the mediastinal pleura posteriorly
- Parallel to the vertebral column
- Run from T1 through T12 where they become continuous with costal lines
What are the recesses? (2)
- Costodiaphragmatic recesses
- Costomediastinal recesses
What is the Costodiaphragmatic recess? (2)
- Surround upward convexity of the diaphragm
- Inferior borders of lungs descend into these recesses
What is the Costomediastinal recess? (2)
- Between costal and mediastinal pleurae
- Left recess is larger
What is the pulmonary ligament?
- Hangs inferiorly from the root of long where visceral and parietal pleura meet as a sleeve surrounding the structures passing to and from the lungs
- Expands to allow movement of lung root and expansion of pulmonary veins
Blood supply of pleurae: Parietal (6)
Post. Intercostal aa.
Int. thoracic aa.
Musculophrenic aa.
Thoracic aorta
Sup. Intercostal aa.
Subcostal aa.
Blood supply of pleurae: Visceral
Bronchial aa.
Nerve supply of pleurae: Parietal (2)
- Somatic nerves-
2nd -12th IC nn. (sensory) - Phrenic nn.
(pain sensitive)
Nerve supply of pleurae: Visceral
Autonomic fibers- Sympathetic fibers from T2-T5
Lymph drainage of pleurae: Parietal
Axillary nodes
Lymph drainage of pleurae: Visceral
Lymph nodes on hilum of lungs
Describe the apex of the lung.
Blunt superior end ascending above the level of the 1st rib
Describe the base of the lung.
Concave inferior surface opposite to the apex, resting on and accommodating the ipsilateral dome of the diaphragm
General features:
Lobes (2 or 3) created by _______ (1 or 2)
fissures
What are the 3 surfaces and 3 borders of the lungs?
o 3 surfaces (costal, mediastinal and diaphragmatic)
o 3 borders (anterior, inferior and posterior)
Describe the apex of the lung.
Blunt superior end ascending above the level of the 1st rib
What are the features of the right lung? (4)
- has oblique and horizontal fissures
- 3 lobes- superior, middle and inferior
- Larger and heavier than left lung
- Shorter and wider than left lung since dome of diaphragm is higher, and the heart bulges more to the left
What are the features of the left lung? (3)
- Single oblique fissure
- 2 lobes- superior and inferior
- Anterior border has a cardiac notch due to left
deviation of the heart