Do you know the extra-oesophageal landmarks?

With POEM, knowing the landmarks outside of the oesophagus has become something which endoscopists are expected to be familiar with. Here is a quick self-test! 
AT WHICH POSITION OF THE 'CLOCKFACE' DO YOU FIND THE:

■ Spine

6 o'clock

■ Anterior vagal trunk

12 o'clock

■ Posterior vagal trunk

6 o'clock

■ Thoracic duct

5 o'clock

■ Left lung

9 o'clock

■ Aorta

7-8 o'clock

■ Azygous vein

4 o'clock - runs in the posterior mediastinum, on the right side of thoracic vertebral column. It drains into the SVC, and returns blood from the posterior walls of the thorax and the abdomen.

explanation

Well the correct answers are: 

a) Spine - 6 o'clock
b) Anterior vagal trunk - 12 o'clock
c) Posterior vagal trunk - 6 o'clock
d) Thoracic duct - 5 o'clock
e) Left lung - 9 o'clock
f) Aorta - 8 o'clock
g) Azygous vein - 4 o'clock

The images below tells the whole story!