Pleural Cavity/pleura

Question 1

Define pleura

Answer 1

Pair of serous membranes lining the thorax and enveloping the lungs.

Question 2

Types of pleura

Answer 2

Visceral pleura
Parietal pleura

Visceral and parietal pleura are continuous with each other at the Hilum/root of the lung.

The pleural cavity is the potential space between visceral and parietal pleura.

Question 3

Visceral pleura

Adherent to
Function

Answer 3

• adheres to all surfaces of lungs.
• cannot be dissected of the surface of the lungs.
• provides Lung with smooth slippery surface so that it can move freely on parietal pleura.

Question 4

Parietal pleura

Adherent to
Function

Answer 4

• lines pulmonary cavities
• adheres to thoracic wall, mediastinum and diaphragm.
• can be dissected if the surfaces it covers.
  Has 3 parts

Question 5

What are the 3 parts of parietal pleura?

Answer 5

Costal
Mediastinal
Diaphragmatic

Question 6

Costal part of parietal pleura

Answer 6

• covers internal surface of the thoracic wall.
• separated from the internal surface of the thoracic wall by endothoracic fascia.
• endothoracic fascia forms natural cleavage plans for surgical separation of the costal pleura from the thoracic wall.

Question 7

Mediastinal part of parietal pleura

Answer 7

• Covers the lateral aspect of mediastinum

- Separates pulmonary cavities and their pleural sacs.

Question 8

Diaphragmatic part

Answer 8

• covers the superior surface of the diaphragm.

- connected to the diaphragm by phrenicopleural fascia( thin more elevations layer of endothoracic fascia)

Question 9

Cervical pleura

Answer 9

• covers the apex of the lung
• reinforced by suprapleural membrane( fibrous extension of endothoracic fascia)
• Suprapleural membrane attaches to the internal border of the first rib and transverse process of C7 vertebra.

Question 10

Pleural reflection

Answer 10

• right and left sternal lines of pleural reflection
• costal lines of pleural reflection
• vertebral lines of pleural reflection

Question 11

Describe the right and left sternal lines of pleural reflection

Answer 11

• asymmetrical due to deviation of the heart to the left side.
• sternal lines are sharp or abrupt and occur where the costal pleura is continuous with the mediastinal pleura anteriorly.

Question 12

Describe the costal lines of pleural reflection

Answer 12

• sharp continuations of the sternal lines

- occurring where the costal pleura becomes continuous with diaphragmatic pleura inferiorly.

Question 13

pleurisy

Answer 13

• inflammation of pleura
• results in exudate coating the pleural surfaces which causes roughening of the pleural surfaces.
• roughening produces friction.
• roughening is detectable using a stethoscope.
• fibroblasts invade exudate releasing collagen which forms pleural adhesions that bind pleural and visceral pleura together.
• results in sharp chest pain during breathing and shortness of breath.

Question 14

pleural effusion

Answer 14

• presence of excess serous fluid in the pleural cavity.
• causes :
  collapsed lung
  inflammation
  malignancy
  congestive heart disease

Question 15

Hemothorax

Answer 15

• Entrance of blood into the pleural cavity.
• causes :
  more commonly caused by injury to major intercostal or internal thoracic vessel rather than from laceration of a lung.

Question 16

Fibrosis

Answer 16

- lung tissue becomes damaged and hard.
causes 
- chronic inflammatory processes 
- infections 
- environmental agents (asbestos)
- exposure to ionising radiation

Question 17

Pleural pain

Answer 17

visceral pleura is insensitive to pain as it receives no nerves of general sensation.

The parietal pleura (particularly the costal part) is extremely sensitive to pain.

The parietal pleura is richly supplied by branches of the intercostal and phrenic nerves.

Irritation of the parietal pleura may produce local pain or referred pain projected to dermatomes supplied by the same spinal (posterior root) ganglia and segments of the spinal cord.

Irritation of the costal and peripheral parts of the diaphragmatic pleura results in local pain and referred pain to the dermatomes of the thoracic and abdominal walls. Irritation of the mediastinal and central diaphragmatic areas of parietal pleura results in referred pain to the root of the neck and over the shoulder (C3–C5 dermatomes).