AN23.1-6 | Mediastinum — Summary & Reflection

REFLECT

KEY TAKEAWAYS

Mediastinum — Key Points:

1. Divided into superior (above T4/T5) and inferior (anterior, middle, posterior)
2. Superior: thymus → brachiocephalic veins → aortic arch → trachea → oesophagus (A→P)
3. Posterior: oesophagus, descending aorta, azygos system, thoracic duct, sympathetic chains
4. Thoracic duct: enters T12 (right), crosses left at T5, drains into left subclavian vein
5. Oesophagus: 4 constrictions; T10 hiatus; dual blood supply → varices in portal hypertension
6. Vagus: right loops under subclavian artery; left loops under aortic arch (at ligamentum)
7. Phrenic: lateral to pericardium, anterior to hilum; C3,4,5 keep the diaphragm alive