Superior and Posterior Mediastinum

Question 1

What is the mediastinum?

Answer 1

The space between the right and left pleural cavities in the thorax

Question 2

What is the superior mediastinum?

Answer 2

The mediastinum above T4/5

Question 3

What is the inferior mediastinum?

Answer 3

The mediastinum below T4/5

Question 4

What is the anterior mediastinum?

Answer 4

The space in the inferior mediastinum anterior to the heart

Question 5

What is the middle mediastinum?

Answer 5

The heart

Question 6

What is the posterior mediastinum?

Answer 6

The space in the inferior mediastinum posterior to the heart

Question 7

What is in the superior mediastinum from superficial to deep?

Answer 7

• thymus
  
  • great veins
  • aortic arch (with vagus and phrenic nerves)
  • trachea
  • oesophagus
  • thoracic duct
  • left recurrent laryngeal nerve

Question 8

Where do the internal jugular veins and subclavian veins unite to form the brachiocephalic veins?

Answer 8

Behind the medial ends of the clavicle

Question 9

Where do the brachiocephalic veins unite to form the SVC?

Answer 9

Behind the first right costal cartilage

Question 10

Where does the SVC enter the right atrium?

Answer 10

Behind the 3rd right costal cartilage

Question 11

Where does the SVC receive the azygous vein?

Answer 11

Behind the 2nd right costal cartilage

Question 12

What are the branches of the arch of the aorta?

Answer 12

left and right coronary arteries, brachiocephalic trunk, left common carotid, left subclavian

Question 13

What is the ligamentum arteriosum?

Answer 13

A fibrous band connective the underside of the arch of the aorta to the pulmonary trunk - remnant of the ductus arteriosum

Question 14

What may be the result of a 4th branch of a right subclavian artery?

Answer 14

Compresses the oesophagus and patient presents with difficulty swallowing

Question 15

What are the roots of the phrenic nerve?

Answer 15

C3,4,5 ventral rami

Question 16

What is the path of the phrenic nerve?

Answer 16

Descends on scalenus anterior, travels between the subclavian artery and vein, passes anterior to the lung root, pierces the diaphragm

Question 17

Where does the right phrenic nerve pierce the diaphragm?

Answer 17

With the IVC

Question 18

Where does the left phrenic nerve pierce the diaphragm?

Answer 18

Alone

Question 19

What are the most later structures in the mediastinum?

Answer 19

The phrenic nerve

Question 20

What is the path of the vagus nerve?

Answer 20

Runs in the carotid sheath between the jugular vein and carotid artery, travels alongside the trachea, passes posterior to the lung root, forms the oesophageal plexus on the anterior surface of the oesophagus, pierces the diaphragm with the oesophagus

Question 21

What is the path of the left recurrent laryngeal nerve?

Answer 21

Branches off the left vagus nerve as it god spast the arch of the aorta, hooks around the ligamentum arteriosum, travels back up in the groove between the trachea and oesophagus

Question 22

What is the path of the right recurrent laryngeal nerve?

Answer 22

Branches off the right vagus nerve at the subclavian artery

Question 23

Where does the trachea divide into the R and L main bronchus?

Answer 23

At T4/5

Question 24

Where does the oesophagus pierce the diaphragm

Answer 24

At T10 to the left of the midline

Question 25

Where does the thoracic aorta pierce the diaphragm?

Answer 25

At T12 between the crura

Question 26

What are the structures of the posterior mediastinum?

Answer 26

descending thoracic aorta, oesophagus, vagus plexus, thoracic duct, azygous vein, sympathetic trunks

Question 27

What are the branches of the descending thoracic aorta?

Answer 27

intercostal arteries, bronchial arteries, oesophageal branches, pericardial branches

Question 28

What is the path of the azygous vein?

Answer 28

Ascends on RHS of vertebral column, arches over right lung root, enters SVC at the level of the 2nd right costal cartilage

Question 29

What veins does the azygous vein receive?

Answer 29

The bronchial, pericardial, intercostal and oesophageal veins

Question 30

What is the path of the thoracic duct?

Answer 30

Begins at the cistern chili, ascends at the back of the oesophagus, empties into the venous system at the junction of the left internal jugular vein and left subclavian vein