Thoracic Cavity

Question 1

What are the components of the thoracic cavity?

Answer 1

• Lungs
• Trachea
• Heart
• Oesophagus
• Great vessels
• Azygos system
• Thoracic duct
• Sympathetic trunk
• Thymus gland
• Bronchi
• Pleural membranes

Question 2

What nerves are found in the thoracic cavity?

Answer 2

• Vagus and phrenic

- Sympathetic chain and splanchnic nerves

Question 3

What are the components of the serous pericardium?

Answer 3

• Parietal layer

- Visceral layer

Question 4

Describe the vagus nerve and what are its two branches?

Answer 4

• Runs down with the carotid artery

- Right and left recurrent laryngeal nerve

Question 5

Describe the passage of the L recurrent laryngeal nerve

Answer 5

• Loops under arch of aorta

Question 6

Describe the passage of the R recurrent laryngeal nerve

Answer 6

• Under right subclavian vein

- More posterior to phrenic nerve

Question 7

Where do the pleural membranes join?

Answer 7

• Root of the lung

Question 8

Which pleura is thicker?

Answer 8

• Parietal

Question 9

What happens to the pleural membranes at the base of the lung?

Answer 9

• Part to form costodiaphragmatic recesses for lung expansion
• T12 at the back up to T6 in the front follow fissures of the lung

Question 10

What are the 5 layers of the visceral pleura?

Answer 10

1) Mesothelial layer- serous fluid
2) CT layer
3) Superficial layer (elastic)- stretch
4) Loose subpleural CT layer (vessels, nerves)
5) Deep fibre-elastic layer

Question 11

Which pleural membrane is sensitive to pain, touch, temp and pressure?

Answer 11

• Parietal pleura

Question 12

What nerve supplies the costal pleura?

Answer 12

• Ribs

- Intercostal nerve

Question 13

What nerve supplies the mediastinal part of the parietal pleura?

Answer 13

• Heart

- Phrenic nerve

Question 14

What nerve supplies the diaphragmatic pleura?

Answer 14

• Diaphragm
• Phrenic
• Lower 6 intercostal nerves

Question 15

What is the visceral pleura sensitive to?

Answer 15

• Stretch but not pain and touch

Question 16

What is the nervous supply of the visceral pleura?

Answer 16

• Pulmonary plexus

- PNS and SNS only

Question 17

What is the blood supply of the parietal pleura?

Answer 17

• Intercostal, internal thoracic and musculophrenic

Question 18

What is the blood supply of the visceral pleura?

Answer 18

• Bronchial vessels

Question 19

Describe the lymphatic drainage of the parietal pleura

Answer 19

• Intercostal, mediastinal, diaphragmatic lymph nodes

Question 20

Describe the lymphatic drainage of the visceral pleura

Answer 20

• Bronchopulmonary lymph nodes in the hilum of the lung

Question 21

What does the pleural membrane connect and why?

Answer 21

• Connection between the rib cage and the lung tissue

- As both layers are connected to each other

Question 22

What are the two recesses of the lung and what is their function?

Answer 22

• Costodiaphragmatic
• Mediastinal
• Allow expansion of the lung

Question 23

What is pleural effusion?

Answer 23

• Fluid build-up in the pleural cavity
• Meniscus (upright)
• Decubitus (meniscus on the side)

Question 24

What is a pneumothorax?

Answer 24

• Air in the pleural cavity
• Collapsed lung due to elastin
• Uncoupling of lung from chest wall
• Likely to be one-sided- comprises saturation, less ventilation

Question 25

What type of pneumothorax might occur during trauma?

Answer 25

- Tension pneumothorax - Penetrating injury - Wound acts as a valve - Increased air in pleural cavity - This can cause tracheal deviation towards the normal lung

Question 26

What are the signs of pneumothorax?

Answer 26

- Chest pain - Shortness of breath - Increased heart rate - Cyanosis

Question 27

How can a tension pneumothorax result in cardiac arrest?

Answer 27

- Mediastinum shifted towards normal lung - Obstructs venous return - Circulatory instability - Cardiac arrest, therefore quick treatment

Question 28

What is thoracentesis?

Answer 28

Fluid taken from pleural space- diagnostic/therapeutic

Question 29

What structures do you have to go through to reach the parietal pleura in thoracentesis?

Answer 29

- Skin, subcutaneous fat, internal and external intercostal muscles, innermost intercostal muscles, fascia, parietal pleua - Draw fluid

Question 30

What is a chest drain?

Answer 30

- Removal of fluid from a cavity - Triangle of safety - 5th intercostal space as there are no major vessels or nerves

Question 31

Where is the mediastinum found?

Answer 31

At the sternal angle

Question 32

What are the contents of the superior mediastinum?

Answer 32

- Arch of aorta, pulmonary trunk, oesophagus, trachea, recurrent laryngeal nerve

Question 33

What are the contents of the anterior inferior mediastinum?

Answer 33

- Thymus - Internal thoracic arteries and veins - Lymphatics and lymph nodes

Question 34

What are the contents of the middle inferior mediastinum?

Answer 34

- Heart and pericardium - Ascending aorta - Pulmonary trunk - Sup and inf vena cava - R+L pulmonary veins, arteries, phrenic nerves - Lymph nodes

Question 35

What are the contents of the posterior inferior mediastinum?

Answer 35

- Oesophagus - Thoracic duct - Sympathetic trunk - Azygos system - Vagus nerves - Primary bronchi

Question 36

What are the boundaries of the thoracic inlet?

Answer 36

- Posteriorly- first thoracic vertebra (T1) - Laterally- first pair of ribs - Forms lateral C-shaped curves posterior to anterior - Anteriorly- costal cartilage of 1st rib and superior border of manubrium

Question 37

What structures pass through the midline of the thoracic inlet?

Answer 37

- Trachea - Oesophagus - Recurrent laryngeal nerves - Thoracic duct

Question 38

What structures pass through posteriorly through the thoracic inlet from medial to lateral?

Answer 38

- Sympathetic trunk - Supreme intercostal vein - Superior intercostal artery