Session 2 - The pleura

Question 1

What is the pleura?

Answer 1

• A serous membrane consisting of a single layer of mesothelial cells with a thin layer of underlying connective tissue

Question 2

What is the parietal pleura?

Answer 2

• Lines the inside of the hemithorax and becomes continuous at the hilum of the lung with the visceral pleura.

Question 3

What does the visceral pleura line?

Answer 3

• Extends between the lobes of the lung into the depths of the oblique and horizontal fissures

Question 4

What is the blood supply of the pleura?

Answer 4

• The intercostal and internal thoracic arteries and veins

Question 5

What is the innervation of the pleura?

Answer 5

• Both somatic (intercostal and phrenic nerves) and autonomic

Question 6

What is pleural space?

Answer 6

• A potential space between two layers of pleura which are continuous at the hilum

Question 7

What is the purpose of pleural fluid?

Answer 7

• Allows the two layers of the pleura to slide over one another with minimal friction.

Question 8

What is the blood and nerve supply to the parietal pleura?

Answer 8

• The intercostal arteries and internal thoracic arteries

* Somatic innervation from phrenic and intercostal nerves

Question 9

What is the blood and nerve supply to the visceral pleura?

Answer 9

• Bronchial arteries and drained by the bronchial veins

* Only autonomic innervation

Question 10

What is the pleural cavity?

Answer 10

• A potential space between two layers of pleura that are continuous at the hilum

Question 11

What does the pleura fluid allow?

Answer 11

• Two layers to slide on one another

Question 12

What are the lines of pleural reflection?

Answer 12

• The lines along which the parietal pleura change direction

Question 13

Give three lines of pleural reflection

Answer 13

• Sternal
• Costal
• Diaphragmatic

Question 14

Where does the trachea commence?

Answer 14

• At the lower border of the cricoid cartilage in the neck

Question 15

What is the angle between the right and left main bronchi known as?

Answer 15

The carina

Question 16

How is the trachea held open?

Answer 16

• By 18-22 C shaped cartilages

Supported posteriorly by trachealis muscle

Question 17

What is the angle between the right and left main bronchi known as?

Answer 17

• Carina

Question 18

What is the cell type which lines the trachea?

Answer 18

Pseudo stratified columnar ciliated epithelium

Question 19

Which bronchus is wider, shorted and more vertical than the other?

Answer 19

• The right

Question 20

What do the primary bronchi divide into?

Answer 20

• Lobar bronchi

Question 21

What is the part of the lung supplied by each segmental bronchus called?

Answer 21

Bronchopulmonary segment

Question 22

Describe a bronchopulmonary segment

Answer 22

• A pyramid shaped area of lung with its apex facing towards the hilum and base towards lung surface.

Each is supplied by a segmental branch of the pulmonary artery and pulmonary vein

Question 23

Why is knowledge of bronchopulmonary segments surgically important?

Answer 23

• Because they can be isolated and removed without much bleeding or air leakage, or intefering with other bronchopulmonary segments

Question 24

What can be visualised with a bronchoscopy?

Answer 24

• The whole inner trachea, the carina, the main bronchi, lobar bronchi and the origin of the segmental bronchi can be visualised

Can be used to see bronchial carcinomas

Question 25

What do bronchial arteries supply?

Answer 25

• Supply the bronchi from Carina to the respiratory bronchioles, visceral pleura and connective tissue

Question 26

Outline the arterial supply of the thorax

Answer 26

* Thoracic aorta -> 2x left bronchial | * Thoracic aorta -> 3rd intercostal -> 1xRight Bronchial

Question 27

Outline the pulmonary circulation of the lungs

Answer 27

• Pulmonary trunk -> Pulmonary -> Lobar -> Segmental

Question 28

Outline pulmonary drainage of the lungs

Answer 28

* Two pulmonary veins on each side | * Middle lobe vein is a major tributary of the right superior pulmonary vein

Question 29

What do the superficial group of bronchial veins drain into on the left?

Answer 29

• Drain visceral pleura and bronchi in the hilar region to the accessory hemiazygous vein

Question 30

What do the superficial group of bronchial veins drain into on the right?

Answer 30

Drain visceral pleura and bronchi in the hilar region to the azygous vein

Question 31

What do the deep bronchial veins drain and into what do they do this?

Answer 31

• Deep bronchi into main pulmonary vein or directly into left atrium probable impossible

Question 32

What do the parietal pleura line?

Answer 32

• The costal, diaphragm and mediastinal surfaces of each hemi thorax

Question 33

What is a line of pleural reflection?

Answer 33

• Relatively abrupt lines along which the parietal pleura changes direction from the costal surface to the diaphragmatic surface and mediastinal surface

Question 34

Where does the apex of the pleural cavity and lung extend?

Answer 34

About 3cm above the medial part of the clavicle

Question 35

What can you deduce if a patient presents with a harmless looking bulge in the supra-clavicular fossa?

Answer 35

• The supra pleural membrane which prevents the lungs and pleura bulging into the neck is not present

Question 36

Where do the anterior borders of the pleural cavitys descend to?

Answer 36

• Behind the sternoclavicular joint to reach the midline at the level of the sternal angle

Question 37

Describe the pat of the right pleural cavity

Answer 37

• Descends vertically to reach the 6th costal cartilage • Then loops round, crossing ○ The 8th rib at the midclavicular line ○ The 10th rib at the midaxillary line ○ The 12th rib in the back (scapular line) ○ Then ascends vertically with the paravertebral muscles

Question 38

Describe the path of the left pleural cavity

Answer 38

• Deviates to the edge of the sternum, then descends vertically to reach the 6th costal cartilage • Then loops round, crossing ○ The 8th rib at the midclavicular line ○ The 10th rib at the midaxillary line ○ The 12th rib in the back (scapular line) ○ Then ascends vertically with the paravertebral muscles

Question 39

Where do the lungs not fill the pleura?

Answer 39

* The lower margins | * In front of the heart

Question 40

How much higher is the lower margin of the lung than the lower margin of the pleura?

Answer 40

Two ribs higher

Question 41

Describe the path of the lungs

Answer 41

* Crosses 6th rib at the midclavicular line * 10th rib at the midaxillary line * 10th rib in the back Ascends vertically with paraverterbral muscles

Question 42

What does the left lung have which means it skirts the pericardium?

Answer 42

* Cardiac notch * From the sternal angle, neraly reaches midclavicular line before curving round to the hearts apex in the 5th intercostal space

Question 43

Where does the oblique fissure extend to and from?

Answer 43

* Between upper and lower lobes | * Extends from spinous proces of T2 verterbra posteriorly to the 6th costal cartilage anteriorly

Question 44

Where does the horizontal fissure extend to and from in the right lung?

Answer 44

• Mid axillary line, anteriorly along the 4th rib to the anterior edge of the lung

Question 45

Why is it important to know the extent of the lungs and pleura?

Answer 45

• During clinical examination of the lungs and in interpreting chest x-raus

Question 46

Name three procedures which can cause pneumothorax (air in the pleural cavity)

Answer 46

* Exposure of the kidney * Liver biopsy * Insertion of a sub-clavicular canulation line into the subclavianvein

Question 47

Name three organs the lower parts of the abdominal organs overlap with

Answer 47

* Liver * Kidney * Spleen

Question 48

Name two structures that lie below the apices of the pleura

Answer 48

* Subclavian vessels an | * Brachial plexus