3-F Mediastinum

Question 1

What are the borders of the mediastinum?

Answer 1

between the thoracic inlet/ diaphragm, the sternum and the vertbral column and within the mediastinal pleura

Question 2

The mediastinum is divided into superior and inferior by a horizonal plane located where?

Answer 2

at the level of the carina

Question 3

What are the three divisions of the inferior mediastinum?

Answer 3

middle, anterior and posterior

Question 4

What are the 5 layers of the superior subvision of the mediastinum?

Answer 4

digestive, respiratory, aterial, venous and the glandular layers

Question 5

What are contained in the 5 layers of the superior subdivision?

Answer 5

i. Digestive layer: esophagus, ii. Respiratory: the trachea, iii. Arterial layer: aortic arch and its branches: brachiocephalic artery, left common carotid artery, left subclavian, iv. Venous layer: superior vena cava and tis tributaries: right and left brachiocephalic veins, iv. Venous layer: superior vena cava and tis tributaries: right and left brachiocephalic veins, v. Glandular layer: the thymus

Question 6

What is contained in the anterior subdivision between the pericardium and the sternum?

Answer 6

mosly fat, lymph and branches of the internal thoracic artery

Question 7

What is contained in the middle subdivision of the mediastinum?

Answer 7

between the pericardium and the vertebral column, contains the heart within the pericardial sac

Question 8

What is contained in the posterior subdivision between the pericaridium and the vertebral column?

Answer 8

the descending aorta, the thoracic duct, azygos vein, hemiazygous vein, esophagus, vagus nerves and sympathetic trunks

Question 9

Superior mediastinum and inferior mediastinum are divided by a horizontal plain that intersects which vertebra?

Answer 9

T4-5, which is at the level of the carina

Question 10

Name the three regions of the mediastinum and their contents.

Answer 10

middle mediastinum (pericardium and all its contents) anterior mediastinum (between pericardium and sternum) posterior mediastinum (between pericardium and vertebral column

Question 11

Which two veins come together to form the brachiocephalic veins

Answer 11

internal jugular and subclavian veins (right being more vertical and left being more oblique, down and rich across the midline)

Question 12

Where does the left vagus nerve inter the thorax and where does it pass?

Answer 12

enters the superior mediastinum, passing anterior to the aortic arch and gives off the left recurrent laryngeal nerve (passes under the aortic arch inferior to the ligamentum arteriosum