Midterm I: Thorax Contents (Ben)

Question 1

What are the 3 divisions of the mediastinum?

Answer 1

1. Anterior Mediastinum
   
   • Cardiac + Supracardiac Parts
2. Posterior Mediastinum

Question 2

What are the contents of the supracardiac mediastinum in ventro-dorsal order?

4 things

Answer 2

1. Thymus (or retrosternal fat pad in adults)
2. SVC + Brachiocephalic Veins
3. Aortic Arch + its branches
4. Trachial Bifurcation + root of lung

• TVAT = Thymus, Veins, Aorta, Trachea

Question 3

What separates the anterior + posterior mediastinum?

Answer 3

Tracheal Bifurcation + Root of Lung

Question 4

What are the contents of the posterior mediastinum?

(Ventro-dorsal order is tougher here because of the crossing of structures, but try to do it.)

Answer 4

1. Thoracic Aorta + branches
2. Esophagus (starts behind, then right, then in front of aorta)
3. Vagus Nerves (right is behind, left in front of esoph.)
4. Thoracic Duct
5. Azygos (right), Hemiazygos + Acc. Hemiazygos Veins
6. Sympathetic Trunk + Splanchnic Nerves

• AEVDASS - Aorta, Esoph, Vagus, Duct, Azygos, Symp + Splanchnic

Question 5

Describe the vessel + bronchus arrangement of the root of the right lung.

Answer 5

Bronchus is eparterial (at + above level of pulmonary arteries)

Pulmonary arteries (C) are above pulm. veins (D).

Question 6

What are the important grooves/impressions on the mediastinal surface of the right lung?

5 things

Answer 6

1. Subclavian Artery Groove
2. IVC Groove
3. Azygos Groove
4. Esophageal Impression
5. Cardiac Impression

The right lung is totally SIAEC, brah.

Question 7

Describe the vessel + bronchus arrangement of the root of the left lung.

Answer 7

Bronchus is hyparterial (below the pulmonary artery)

Artery is on top, with veins in front of and below bronchus.

Question 8

What are the important grooves/impressions on the mediastinal surface of the left lung?

Answer 8

1. Left Subclavian Artery Groove
2. Aortic Arch Groove
3. Thoracic Aorta Groove
4. Cardiac Impression

Question 9

What is indicated by the bottom green arrow?

What is it made up of and what does it do?

Answer 9

Pulmonary Ligament

• a fold of parietal pleura which holds the lower parts of the lungs in place

Question 10

What are the two important spaces between the layers of the pleura which allow expansion of the lungs on inspiration?

Answer 10

Costomediastinal + Costodiaphragmatic Recesses

• visible as the light blue areas behind the ribs in the picture
• CM recess is most easily visible near the cardiac notch, but exists on the right side as well
• CD recess is below the lung + allows for most of the expansion

Question 11

To what level do the two domes of the diaphragm extend?

(I assume in resting, expiration state but Agota didn’t say)

Answer 11

Left dome = 5th IC space

Right dome = 4th IC space (due to liver)