Mediastinum

Question 1

Divisions

Answer 1

Superior

• trachea, esophagus, thymus, phrenic nerve, Azygous vein, SVC, brachiocephalic artery & vein, aortic arch, left common carotid artery, left subclavian artery & thoracic duct
• aortic arch aneurysm, esophageal perforation (from endoscopy or invading malignancy), traumatic rupture of trachea

Anterior

• thymus, lymph nodes, fats, connective tissue
• Thymoma (associated with myasthenia gravis, RBC aplasia), thyroid mass, germinal cell neoplasm, lymphoma

Middle

• heart, pericardium, phrenic nerve, ascending aorta, SVC, IVC, coronary artery & vein
• pericardial cysts, branchiogenic cysts, sarcoidosis

Posterior

• descending aorta, esophagus, thoracic duct, azygous vein, splanchnic nerve, vagus nerve, sympathetic trunk
• ganglioneuromas, neuroblastomas, esophageal diverticula or neoplasms

Question 2

Fetal structures

Answer 2

R & L umbilical arteries

L umbilical vein

Ductus venosus

Foramen ovale

Ductus arteriosus

Question 3

Adult structures

Answer 3

Medial umbilical ligaments

Ligamentum teres

Ligamentum venosum

Fossa ovale

Ligamentum arteriosum

Question 4

Space between pleural cavities in the thorax

Boundaries:

• Lateral: pleural cavities
• Anterior: sternum
• Posterior: vertebral column

Answer 4

Mediastinum