Pleura

Question 1

what 2 layers is the pleura made up of

Answer 1

-outer parietal layer
-inner visceral layer

Question 2

what is the parietal pleura divided into

Answer 2

• Costal pleura
• Diaphragmatic pleura
• Mediastinal pleura
• Cervical pleura

Question 3

what does the costal pleura line

Answer 3

Lines the inner surface of the thoracic wall, but separated from it by endothoracic fascia

Question 4

what does the Diaphragmatic pleura cover

Answer 4

Covers the superior surface of the diaphragm

Question 5

what does the Mediastinal pleura line

Answer 5

Lines the corresponding surface of the mediastinum and forms its lateral boundary. Over the root of the lung it becomes continuous with the visceral pleura

Question 6

how does the cervical pleura extend

Answer 6

It is the dome of parietal pleura which extends into the root of the neck. It is called cupola and covers the apex of the lung, hence care should be taken while penetrating this area with anesthetic needle. It is covered by suprapleural membrane or Sibson’s fascia.

Question 7

what is the pulmonary ligament formed by

Answer 7

After surrounding the root of the lung the pleura extends down as a fold called pulmonary ligament

Question 8

what is the pulmonary ligament filled with

Answer 8

loose areolar tissue and contain few lymphatics

Question 9

what is the function of the pulmonary ligament

Answer 9

It provides dead space for the expansion of inferior pulmonary vein during high venous return as in exercise

It allows the descent of the root of the lung with the descent of the diaphragm during inspiration

Question 10

what is the surface marking of the cervical pleura

Answer 10

Marked by a curved line (convexity directed upwards) drawn from sternoclavicular joint to the junction of medial third and middle third of the clavicle. The summit of the dome of pleura lies 1 inch above the medial one-third of the clavicle.

Question 11

what is the surface marking of the Anterior (costomediastinal) line of pleural reflection

Answer 11

On the right side-
It extends downwards and medially from the right sternoclavicular joint to the midpoint of the sternal angle, then descends vertically up to the midpoint of the xiphisternal joint

On the left side-
It extends downwards and medially from the left sternoclavicular joint to the midpoint of the sternal angle, then descends vertically only up to the level of the 4th costal cartilage.

Question 12

what is the surface marking of the inferior (costomediastinal) line of pleural reflection

Answer 12

On the right side-
The line of pleural reflection starts from the xiphisternal joint or behind the xiphoid process and crosses the 8th rib in the midclavicular line, 10th rib in the midaxillary line and 12th rib at the lateral border of the erector spinae muscle, 2cm lateral to the spine of T12

On the left side-
The line of pleural reflection starts at the level of the 6th costal cartilage, about 2cm lateral to the midline. Thereafter it follows the same course as on the right side

Question 13

where is the Costomediastinal recess

Answer 13

Lies anteriorly behind the sternum and costal cartilages, between the costal and mediastinal pleura
Prominent in the cardiac notch of the lung

Question 14

where is the Costo-diaphragmatic recess

Answer 14

Lies inferiorly between the costal and diaphragmatic pleurae. The line of this reflection is two ribs lower than the lower border of the lung. So this recess is not filled by lung during quiet inspiration and is partially filled by lung during deep inspiration.

Question 15

what is the development of the parietal pleura

Answer 15

develops from somatopleuric layer of lateral plate mesoderm

Question 16

what is the nerve supply of the parietal pleura

Answer 16

Supplied by somatic nerves – intercostal and phrenic nerve
Costal and peripheral part of diaphragmatic pleura are supplied by intercostal and phrenic nerves
Mediastinal and central part of diaphragmatic pleurae are supplied by phrenic nerve

Question 17

what is the arterial supply of the parietal pleura

Answer 17

by branches from the intercostal, internal thoracic and musculophrenic arteries

Question 18

where do the veins of the parietal pleura drain

Answer 18

into azygos and internal thoracic veins

Question 19

what is the lympathic drainage of the parietal pleura

Answer 19

Lymphatics drain into intercostal, internal mammary, posterior mediastinal and diaphragmatic nodes

Question 20

how does the pulmonary pleura develop

Answer 20

from splanchnopleuric layer of lateral plate mesoderm

Question 21

what is the nerve supply of the pulmonary pleura

Answer 21

Supplied by autonomic (sympathetic) nerves (T2-T5), which accompany the bronchial vessels

Question 22

what is the blood supply of the pulmonary pleura

Answer 22

bronchial vessels

Question 23

what is the lymphatic drainage of the pulmonary pleura

Answer 23

Lymphatics drain into bronchopulmonary lymph nodes

Question 24

what is the importance of the pleural cavity

Answer 24

-The opposed surfaces of parietal and visceral pleura are lined by mesothelial cells.
They secrete a small quantity of serous fluid into the space continuously which is essential for the movement of the lungs (to prevent rubbing during lung movements).

-A negative pressure is maintained inside the pleural cavity which is necessary to retain visceral pleura in contact with parietal pleura.
If there is positive pressure (i.e., pneumothorax) inside the pleural cavity, the inherent elastic recoil of the lung tissue pulls the visceral pleura away from the parietal pleura causing the collapse of the lung.