Mediastinum

Question 1

What are the parts of the inferior mediastinum?

Answer 1

1. anterior mediastinum: between the sternum and the pericardium
2. middle mediastinum: pericardial sac and its contents
3. posterior mediastinum: behind the pericardium and extends inferiorly between the diaphragm and the posterior chest wall

Question 2

What does the anterior mediastinum contain?

Answer 2

Thymus and adipose tissue

Question 3

What are the borders of the superior mediastinum?

Answer 3

Posterior to manubrium
Anterior to bodies of 1st 4 thoracic vertebrae

Superior boundary: oblique plane passing from jugular notch up and posteriorly to superior border of T1
Inferior border: transverse plane passing from sternum angle to intervertebral disc between vertebra T4/5
Lateral border: mediastinal part of parietal pleura

Question 4

How does the superior vena cava form?

Answer 4

• formed by asymmetric union of right and left brachiocephalic veins
• Left brachiocephalic crosses posteriorly to manubrium to join right brachiocephalic to form SVC
• Also very close to manubrium (veins sit more anterior than arteries)

Question 5

What is the path of the brachiocephalic trunk?

Answer 5

• origin behind manubrium slightly anterior to other branches
• ascends, crossing over to the right side of the trachea
• At sternoclavicular joingt branches into:
  
  • Right common carotid artery
  • Right subclavian artery

Question 6

What is the relation of the left phrenic and vagus nerve to the aortic arch?

Answer 6

pass anterior to the arch.

Question 7

What are the branches of the right vagus nerve?

Answer 7

oesophageal, cardiac and pulmonary plexus

Question 8

What are the branches of the left vagus nerve?

Answer 8

• Oespahgus, pulmonary, cardiac plexus

- Left recurrent laryngeal nerve