Mediastinum

Question 1

Superior mediastinum boundaries

Answer 1

Ant - Manubrium sterni
Post- bodies of first 4 thoracic vertebrae
Sup - Plane of thoracic inlet
Inf - Imaginary plane passing through the sternal angle and the lower part of the body of T4
Each side - Mediastinal Pleura

Question 2

Superior Mediastinum contents

Answer 2

1. Trachea and esophagus
2. Muscles - origins of Sternohyoid, sternothyroid and Lower ends of longus colli
3. Arteries - Aortic arch, brachiocephalic artery, left common carotid, left subclavian
4. Veins - Right and left brachiocephalic veins, superior vena cava, left superior intercostal vein
5. Nerves - Vagus, phrenic, cardiac nerves of both sides, left recurrent laryngeal nerve
6. thymus
7. thoracic duct
8. Lymph nodes - Paratracheal, tracheobronchial, brachiocephalic

Question 3

Anterior Mediastinum Boundaries

Answer 3

Ant - Sternum body
Post - Pericardium
Sup- Imaginary plane passing through the sternal angle and the lower part of the body of T4
Inferiorly - The superior surface of thoracoabdominal diaphragm
Either side - Mediastinal pleura

Question 4

Anterior Mediastinum Contents

Answer 4

1. Sternopericardial ligaments
2. Lymph nodes and lymphatics
3. Small mediastinal branches of the internal thoracic artery
4. Lower end of thymus
5. Areolar tissue

Question 5

Middle Mediastinum Boundaries

Answer 5

Ant - Sternopericardial ligaments
Post - esophagus, azygous vein, descending thoracic aorta
Sup- Imaginary plane passing through the sternal angle and the lower part of the body of T4
Inferiorly - The superior surface of thoracoabdominal diaphragm
Either side - Mediastinal pleura

Question 6

Middle Mediastinum Contents

Answer 6

1. Heart enclosed in pericardium
2. Arteries - Ascending aorta, Pulmonary trunk, Left and right pulmonary arteries
3. Veins - Lower part of superior vena cava, terminal part of azygous vein, right and left pulmonary veins
4. Nerves - Phrenic, deep cardiac plexus
5. Lymph nodes - Tracheobroncial nodes
6. Tubes - Bifurcation of the trachea and the left and right primary bronchi

Question 7

Posterior Mediastinum Boundaries

Answer 7

Ant - Pericardium, Bifurcation of trachea, pulmonary vessels, posterior part of the upper surface of the diaphragm
Post - Lower 8 Thoracic vertebrae and intervertebral discs
Sup- Imaginary plane passing through the sternal angle and the lower part of the body of T4
Inferiorly - The superior surface of thoracoabdominal diaphragm
Either side - Mediastinal pleura

Question 8

Posterior mediastinum Contents

Answer 8

1. Esophagus
2. Arteries - Descending Thoracic Aorta and its branches
3. Veins - Azygous vein, Hemiazygous vein, Accessory hemiazygous vein
4. Lymph nodes and lymphatics - Posterior mediastinum lymph nodes that are along the aorta and the thoracic duct
5. Nerves - Vagus nerves, splanchnic nerves (Greater, lesser and least arising from the lower Thoracic vertebra ganglions of the sympathetic chain)